Hovertrek Neoteric (hovercrafts). Manuals

HIRTH 2703 Carburated - 55 hp

The 2703 V is an air cooled, piston controlled 2-cylinder-inline-2-stroke engine with one or two

carburetors and Nikasil coated cylinders. It has one of the highest power to weight ratio available

on the 50 HP engine market. Ideally suited for Ultralights, hovercraft, light experimental aircraft

and all applications where weight is an issue.

Factory recommended TBO is rated at 1000 hours at 75% power. The warranty of the crank shaft

is 3 years.

Technical Data

Specifications subject to change without prior notice

Type:

Two cylinder two stroke (Inline)

Displacement:

521 cm3 (31.79 cu in)

Stroke:

64mm (2.52 in)

Bore:

72mm (2.83 in)

Max. Performance:

38.2 kW (52 HP at 6500 rpm

According to DIN 70020

40.2 kW (55 HP at 6200 rpm

Specification with fan cooling

Max. Torque:

60 Nm (44.2 ft.lb) at 5700 rpm

67 Nm (49.4 ft.lb) at 5600 rpm

Carburation:

2 slide carburetor (Bing Size 54)

Ignition System:

CDI

Generator Power:

250W, 12V

Cooling:

Fan cooling

Weight:

31 kg (68.4lb)

Starting Device:

Recoil starter

Running direction:

Counter-clockwise, view to output shaft

Fuel mixture:

Mixture 1:50, 2-stroke-oil, fuel min. 95 octane (RON)

Form 16013

rev2

HIRTH ENGINE SETTING VALUES

55 HP Engine

Fan cooled engine

Engine

55HP Fan Cooled (FC)

Ign. Timing @ 2000 Carbureted

16° BTC

Spark Plug Heat VI *

280

Spark Plug Gap

0.020-0.024

No. of Carburetors

Two

Carburetor ID #

Bing 54 Carburetor (38mm)

Main Jet

160

Idle Jet

Idle Screw

1 Turn Out

Jet Needle

6P2 Position 1

Needle Jet

2.72

Needle Position

Do not exceed RPM

5800

Peak HP RPM

5500

HP (4i Peak RPM

Peak Torque RPM

5000

Peak Torque Ft. Lb.

53.2

Maximum CHT

535 ° F

Maximum EGT @ full power

1256 ° F

Maximum EGT @ cruise RPM

1330 ° F

Spark Plug *

Compression Pressure

120 PSI

* Optional Plugs : NGK BR 8 HS

: Champion RL86C or #830, L78C

: Nippon Denso W24 FSR-u

: Bosch W3AC

Useful Links:

Official Bing Manual: www.bingcarburetor.com/manual.html

Online Rebuild Manual: www.800-airwolf.com/pdffiles/ARTICLES/part%2052.PDF

Online Tuning Manual: www.ultralightnews.com/enginetroublshooting/techtips/techtips2.htm

Online Cleaning Guide: http://www.light-sport-aircraft.org/bing-54-carburetor-1.htm

Form 16941 rev2

Crankshaft 2703

Fig.

Qty.

Description

Neoteric

Remark / Notes

No.

Part #

Crankshaft, complete

7911

Includes items 2 - 7

Deep groove ball bearing

5460

Deep groove ball bearing

5461

Deep groove ball bearing

5462

Circlip

7912

Shaft sealing ring

5453

Space ring

7913

Needle Bearing, Blue dot (#1)

7909

* Connecting Rods are Color-Coded with a Paint Dot on

the Piston end.

Needle Bearing, Yellow dot (#2)

6082

Engines built from 2010 onward also include a Number

Code next to the Paint Dot. The coding corresponds to the

correct Needle bearing size. (Approx 0.0003" [0.008mm]

graduation between each size)

Needle Bearing, Red dot (#3)

6083

Blue (#1) is the smallest and Green (#5) is the largest.

Connecting rods with a Red (#3) dot are most common.

Needle Bearing, White dot (#4)

5464

If the paint dot is missing and no number code can be

found, all bearings must be tried for the best fit.

Needle Bearing, Green dot (#5)

7910

Part 17118 rev2

55HP Cooling Fan System

(2703)

Fig.

Qty.

Description

Neoteric Part #

Remark / Notes

No.

Includes Fig No.

Fan housing, complete

7938

4, 5, 7, 8, 9, 10, 11, 12

Alignment sleeve

7939

Cylinder screw

3258

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

Hexagon head nut

6855

Torque = 27 - 30 Nm (19.9 - 22.1 ft-lb)

Washer

6856

*Used up to model year 2008

Flat belt

3409

(Engine #901105 & Lower)

Currently used, from 2008 onward

Poly V Flex belt

6390

(Engine #901106 & Higher)

Locking ring

7940

Deep groove ball bearing

6887

Incl. Pos. 8, 9, 11

3408

10*

Fan wheel Assy, Flat belt

*Used up to model year 2008

(5879 - rebuilt)

(Engine #901105 & Lower)

Incl. Pos. 8, 9, 11

Fan wheel Assy, Poly V

6391

Currently used, from 2008 onward

(Engine #901106 & Higher)

Contains all parts required to convert engine

Poly V Cooling System

7457

from “Flat Belt” cooling system to

Conversion Kit

“Poly V Belt” cooling system.

Bushing

7941

Eccentric shaft

6857

Thread screw

5987

Washer

5996

Thread screw

5997

Air guide cowl

5346

Metal plate

6183

Hexagon head nut

2694

Washer

7942

Screw

2693

Washer

7943

Hole Plug

2449

Covers Hole In Housing

Form 17363 rev2

55HP Starting Device

(2703)

Fig.

Qty

Description

Neoteric

Remark / Notes

No.

Part #

Cylinder screw

6911

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

Spring ring

6940

Starter, mounted

5267

Cylinder screw

7944

Torque = 23 - 28 Nm (17 - 20.7 ft-lb)

Tab washer

5995

Driving dog with starter, Flat

6203

*Used up to model year 2008

(Engine #901105 & Lower)

Driving dog with starter, Poly-V

6389

Currently used, from 2008 onward

(Engine #901106 & Higher)

Cylinder screw

2348

Torque = 23 - 28 Nm (17 - 20.7 ft-lb)

Tab washer

5995

Electric Starter, Hirth

6982

Old starter 5545

Electric Starter, Alternative

7563

Replacement for Customers

Starter Solenoid

5417

Hole Plug

9172

Plugs Drain Hole In Starter

Form 17684 rev2

55/65HP Ignition System

Fig.

Qty.

Description

Neoteric

Remark/Notes

No.

Part #

Hexagon head nut

6939

Torque = 140 - 150 Nm (103.3 - 110.6 ft-lb)

Washer

7196

Flywheel with gear ring

7984

Includes fig. 3a, 3b, 33

Cylinder screw

7182

Neoteric does not stock

Washer

5994

Washer

6936

Torque = 4 - 4.5 Nm (3 - 3.3 ft-lb)

Stator plate complete

5591

Flywheel alignment pin

7985

CDI - Box

5664

Mounted with silicone

Coil Mounting Screw

2469

Ignition coil

5682

Includes fig. 15

Spark plug cap

5826

Spark plug

5668

Do not mix spark plug types

Voltage Regulator

9876

Magnet Support

5724

Spark plug lead, short

5666

Wire only; does not include fig. 30

Coil spray guard

6683

Spark plug lead, long

5665

Wire only; does not include fig. 30

Spark Plug lead set

5661

Includes fig. 30, 34, 36

Form 17683 rev2

55HP Hirth Bing Carburetor Parts

(2703)

Fig.

Neoteric

Qty

Description

Remark / Notes

No.

Part #

Main jet

Needle jet

See form 16642 for all Bing Jets

Jet needle

Idle jet

Idle Screw

7954

Idle Screw O-Ring

7955

Throttle slide

7956

Mixture tube

7957

Sieve Sleeve

7958

Bracket plate

6974

Spring Cup

7959

Adjusting screw

7960

Adjustment Screw Spring

7961

Slide Spring

7962

Cover plate

7963

Cover Plate O-Ring

7964

Cover Plate Screw

7965

Adjusting screw

6105

Nut

6106

Socket

6113

Float

7966

Float Pivot Pin

7967

Float Needle

7968

Float Needle Clip

7969

Float chamber

7973

Bowl Gasket

7974

Bowl Clip

7975

Choke Piston

7976

Choke Sleeve

7977

Choke Spring

7978

Choke housing

7979

Vent Tube

7980

Rubber cap for primer

7981

connection

Float chamber

7982

Jet Needle O-ring

7983

Rebuild Kit

6286

Includes fig. 6, 9, 16, 20, 22, 23, 26

Form 17687rev2

HIRTH 3203 Carburated - 65 HP

HIRTH’s most popular engine. The 3203 produces more horsepower and torque per pound than any

other engine in its power class. Hirth 3203 is the forerunner in power plants for the heaviest

ultralight trainers, gyrocopters and light experimentals today.

3203 incorporates Al-Nikasil coated cylinders for superior performance and reliability. Al-Nikasil in

simple terms is a nickel based material, applied in a paste form, when superheated it becomes part

of the cylinder itself. Al-Nikasil provides for a super low coefficient of friction, reducing engine

heat and wear. The pistons and cylinders expand at the same rate thus providing for a seizure

resistant engine. 3203 crankshaft is 4130 chromemolly steel. Heads, cylinders, rings, block casting,

connecting rods and associated components are all of the highest grade alloys available today.

2706 - 65Hp engine shown with fan cooling

Technical Data:

Model:

3203 2 cycle, two cylinder in line

Carburetion:

Dual 38mm slide type or optional fuel injection

fan cooled

Fuel Pump:

Auxiliary external pneumatic

Bore:

2.99” [76 mm]

Lubrication:

Premix - 50:1 ratio or optional oil injection

Stroke:

2.72” [69 mm]

Rotation:

Counter clockwise, viewed from output end

Piston Diameter:

2.986” [75.84mm]

Ring Gap:

0.009” [0.23mm]

Cylinder Diameter:

2.991” [75.97mm]

Starter:

12 VDC electric, recoil or both/250 watt charging.

Displacement:

625 cc

Cooling:

Optional - Axial fan or free air cooled by prop.

Compression:

9.5 : 1

Ignition:

Single CDI (Capacitive discharge Ignition)

HP Output:

65hp [48.5 kW] @ 6300 rpm

Weight:

82 lbs. fan cooled including Elec. Start and exhaust

Torque:

56ft. lbs. [76 Nm] @ 5700 rpm

TBO

1000 Hrs. Rated at 75% power

*Optional Plugs: NGK BR8HS

Champion RL86C or #830

Engine

3203 - 65 HP FC

Ign. Timing @ 2000 Carbureted

16° BTC

Ign. Timing @ 2000 Fuel Injected

18° BTC

Spark Plug Heat VI

280

Spark Plug Gap

0.020-0.024

No. of Carburetors

Two

Carburetor ID #

Dellorto PHBE 34 BD 8

Main Jet

l60 : 155 & 158 Available

Idle Jet

Idle Screw

3/4 Turn Out

Jet Needle

K 35

Needle Jet

AB 268

Needle Position

Cold Start/Choke Jet

Do not exceed RPM

6600

Peak HP RPM

6300

HP @ Peak RPM

Peak Torque RPM

6000

Peak Torque Ft. Lb.

Maximum CHT

535° F

Maximum EGT @ full power

1256°F

Maximum EGT @ cruise RPM

1330°F

Spark Plug Denso

W24 FSR - U10*

Form 16013 rev3

Spare part list - 65 HP Single Ignition

Crankcase 3203

110

Fig.

Neoteric

Qty.

Description

Remark / Notes

No.

Part #

Crankcase, complete

7164

Included Figures 60 - 70

Cylinder screw

7937

Torque = 23 - 25 Nm [17 - 18.4 ft-lb]

Cylinder screw

2289

Torque = 9 - 11 Nm [6.6 - 8.1 ft-lb]

Washer

6916

Threaded Pin Grub Screw

9003

Loctite 243

Stud screw

7163

Loctite 243

Plug tip

7936

Loctite 586

Cylinder screw

9004

Only 1 Required for Carbureted engines

Sealing ring, AL

5629

100

Pulse line / Crank Case vac. nipple

5630

Carburetor engines only.

105

Dust Cover / Boot

7208

110

Oil injection nipple

5490

Oil inj. Engines with fuel inj.

120

Cylinder Base Gasket

5455

See form 17749 for gasket set

Rubber Gasket Sealant

7842

Use as crankcase gasket

Form 17275 rev3

Crankshaft 3203

Fig.

Neoteric

Qty.

Description

Remark / Notes

No.

Part #

Crankshaft, complete

5449

Includes items 2 - 7

Deep groove ball bearing

5460

Deep groove ball bearing

5461

Deep groove ball bearing

5462

Circlip

7912

Shaft sealing ring

5453

Space ring

7913

Needle Bearing, Blue dot (#1)

7909

* Connecting Rods are Color-Coded with a Paint Dot on

the Piston end.

Needle Bearing, Yellow dot (#2)

6082

Engines built from 2010 onward also include a Number

Code next to the Paint Dot. The coding corresponds to the

correct Needle bearing size. (Approx 0.0003" [0.008mm]

graduation between each size)

Needle Bearing, Red dot (#3)

6083

Blue (#1) is the smallest and Green (#5) is the largest.

Connecting rods with a Red (#3) dot are most common.

Needle Bearing, White dot (#4)

5464

If the paint dot is missing and no number code can be

found, all bearings must be tried for the best fit.

Needle Bearing, Green dot (#5)

7910

Part 17756 rev2

Fan cooling system 3203

Fig.

Qty.

Description

Neoteric Part No

Remark/Note

No.

Fan housing,

Includes Fig No.

9020

complete

4, 5, 6, 10*, 12, 19, 20, 21

Alignment sleeve

7939

Cylinder screw

3258

Torque = 6-8 ft lb. (9.6-11 Nm)

Hexagon head nut

6855

Torque = 20 ft lb. (27-30 Nm)

Washer

6856

*Used up to model year 2008

Flat belt

3407

(Engine #901105 & Lower)

Currently used, from 2008 onward

Poly V Flex belt

6390

(Engine #901106 & Higher)

Locking ring

7940

Deep groove ball

6887

bearing

Incl. Pos. 8, 9, 11

Fan wheel Assy,

3408

10*

*Used up to model year 2008

Flat belt

(5879 - modified)

(Engine #901105 & Lower)

Incl. Pos. 8, 9, 11

Fan wheel Assy,

6391

Currently used, from 2008 onward

Poly V

(Engine #901106 & Higher)

Bushing

7941

Eccentric shaft

6857

13-B

Air guide cowl - SI

5324

Single ignition

Thread screw

5997

Cylinder screw

6901

Torque = 6-8 ft lb. (9.6-11 Nm)

Washer

6916

Spring ring

5999

Metal plate

6183

Hexagon head nut

2694

Washer

7942

Screw

2693

23-A

Rubber grommet

For dual ignition engines

23-B

Rubber grommet

9021

For single ignition engines

Cylinder screw

5998

Torque = 6-8 ft lb. (9.6-11 Nm)

Air guide mounting

6928

block

Sheet

5981

Not on Sketch

Hole Plug

2449

Covers Hole In Housing

Form 17753 rev3

65HP Starting Device

(3203)

Fig.

Neoteric

Qty.

Description

Remark/Note

No.

Part #

Cylinder screw

6911

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

Spring ring

6940

Starter, mounted

5267

Cylinder screw

7944

Torque = 23 - 28 Nm (17 - 20.7 ft-lb)

Tab washer

5995

Driving dog with starter,

*Used up to model year 2008

6189

Flat

(Engine #901105 & Lower)

Driving dog with starter,

Currently used, from 2008 onward

6389

Poly-V

(Engine #901106 & Higher)

Cylinder screw

2348

Torque = 23 - 28 Nm (17 - 20.7 ft-lb)

Tab washer

5995

Starter

6982

Old Starter 5545

Alternative Starter

7563

Replacement for Customers

Starter Solenoid

5417

Starter Hole Plug

9172

Used to plug drain hole in starter

Form 17282 rev3

55/65HP Ignition System

Fig.

Qty.

Description

Neoteric

Remark/Notes

No.

Part #

Hexagon head nut

6939

Torque = 140 - 150 Nm (103.3 - 110.6 ft-lb)

Washer

7196

Flywheel with gear ring

7984

Includes fig. 3a, 3b, 33

Low Profile S.H.C.S.

9697

Cylinder screw

7182

Washer

5994

Washer

6936

Torque = 4 - 4.5 Nm (3 - 3.3 ft-lb)

Stator plate complete

5591

Flywheel alignment pin

7985

CDI - Box

5664

Mounted with silicone

Coil Mounting Screw

2469

Ignition coil

5682

Includes fig. 15

Spark plug cap

5827

Spark plug

5668

Do not mix spark plug types

Voltage Regulator

5338

Magnet Support

5724

Spark plug lead, short

5666

Wire only; does not include fig. 30

Spark plug lead, long

5665

Wire only; does not include fig. 30

Spark Plug lead set

5661

Includes fig. 30, 34, 36

Form 17683 rev2

Hirth 65HP Fuel Injection / Fuel mixture

Fig.

Neoteric

Qty.

Description

Remark / Notes

No.

Part #

Reed valve

7203

Intake manifold

6568

Hose clamp

9008

Gasket

5463

Cylinder screw

2292

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

Washer

6916

Throttle manifold

5594

Clamp

6929

Cylinder screw

6901

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

100

Washer

6916

110

Washer

5996

120

Hexagon head nut

9009

130

Hexagon head nut, self.

5572

140

Ground cable

6454

150

Air filter

6622

6904

*Used up to May-2011

160

Fuel Injector, Old Style

(Engine #902754 & Lower)

6903

Currently used, from May-2011 onward

160

Fuel Injector, New Style

(Engine #902754 & Higher)

170

Injector Holding plate

9010

180

Washer

9011

190

Cylinder screw

9012

Loctite 243

7188

Shown in illustration;

200

Pressure regulator, Old Style

*Used up to May-2011

(Engine #902754 & Lower)

7932

200

Pressure regulator, New Style

Currently used, from May-2011 onward

(Engine #902754 & Higher)

200

Pressure regulator, Replacement

7279

Compatible with both old & new styles

210

Pressure regulator holder, complete

9013

220

Cylinder screw

7189

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

230

Washer

6916

240

Cylinder screw

9014

Loctite 243

250

Washer

6936

260

Hexagon head nut

9015

270

Washer

9016

280

Cylinder screw

9017

290

Washer

6936

300

Bushing

6935

Form 16022 rev3

Carburetor (Dellorto) F 33 A (PHBE 34 BD 6832)

Fig.

Neoteric

Qty.

Description

Remark/Note

No.

Part #

Throttle slide

9022

Jet needle, K36

6563

Needle jet

Main jet

See Form # 17367 for all Dellorto Jets

Idle jet, 65

9023

Cold start / Choke jet

7788

Float valve

9024

Float

6909

Rubber cap

6113

*Included in 7828 Kit

Choke Cable Adjustment

7828

*Must Purchase 7828 Kit

Choke Cable Adjustment Locknut

7828

*Must Purchase 7828 Kit

Top Cover Screw

9027

Choke Support Screw

9028

*Must Purchase 7828 Kit

Choke Support Casting

9029

*Must Purchase 7828 Kit

Choke Support O-ring

7828

Included in Pos. 59

Choke Valve Spring

9030

*Must Purchase 7828 Kit

Choke valve

7828

*Must Purchase 7828 Kit

Throttle Slide Spring

9025

Bracket plate

6973

Top Cover O-Ring

9026

Included in Pos. 59

Mixture Adjustment Screw

9031

Mixture Adjustment Spring

9032

Mixture Adjustment Washer

9033

Mixture Adjustment O-ring

Included in pos. 59

Idle Adjustment Screw

9034

Idle Adjustment Spring

9035

Idle Adjustment Washer

9036

Idle Adjustment O-ring

Included in Pos. 59

Fuel Inlet Filter

9037

Fuel Inlet O-ring

Included in Pos. 59

Fuel Inlet Screw

9038

Needle Valve Gasket Washer

Included in Pos. 59

Cold Start / Choke O-ring

Included in Pos. 59

Main jet holding screw

9039

Float Pivot Pin

9040

Sealing for float chamber

9296

Included in Pos. 59

Float Bowl

9041

Float Bowl Gasket Washer

7213

Included in Pos. 59

Float Bowl Gasket O-Ring

2739

Optional Replacement For Washer

Float Bowl Nut

9042

Fuel Inlet Nipple

6114

Carburetor Top Cover

9043

Includes Pos.

Gasket set

5468

16,21,25,29,32,34,35,38,40

Form 17755 rev4

3701- 100Hp

The 3701 is Hirth's first offering of a water-cooled

engine for the aircraft market.

A narrow profile and single tuned exhaust used for

all 3 cylinders allows the 3701 to be used in compact

engine compartments. Pistons fire 120 degrees apart

resulting in very quiet & smooth operations.

3701 incorporates Al-Nikasil coated cylinders for

superior performance and reliability. Nikasil provides

for a super low coefficient of friction, reducing engine

heat and wear. The pistons and cylinders expand at the

same rate thus providing for a seizure resistant engine.

3701 crankshaft is 4130 chromemolly steel. Heads,

3701- engine shown with dual ignition and 90 degree exhaust manifold

cylinders, rings, block casting, connecting rods and

associated components are all of the highest grade

alloys available today.

Carburetion:

3 dellorto carbs

Technical Data:

Old Option: Electronic suction pipe fuel injection

Model:

3701 - 2 cycle, three cylinder inline

Fuel Pump:

3 diaphram pumps (1 for each carb)

Reed valve induction.

Old Option:

90 PST 12VDC electric fuel pump.

Bore:

76 mm

Lubrication:

Premix -40:1 or optional oil injection

Stroke:

69 mm

Displacement:

939 cc

Rotation:

Counter clockwise, viewed from output end

Compression:

9.5 : 1

12 VDC electric / 240 watt generator

Starter/Generator:

HP Output:

100hp @ 6000 rpm

Liquid cooled 50:50 mixture of glycol (anti freeze)

Peak Torque:

88 ft. lbs. @ 5500 rpm

Cooling:

& water

Ignition:

Single CDI (Capacitive Discharge Ignition)

108 lbs, including complete exhaust & starter

TBO

1,000 Hrs. Rated at 75% power

Weight:

Spark Plugs: NKG BR9HS

3701 TECHNICAL DATA

Fuel Injected Engine

3701S--100Hp

Carbureted Engine

Ign.Timing@2000 - Fuel injected

18°

Ign. Timing@2000

16°

Spark Plug Heat VI.

280

No. of Carburetors

Spark Plug Gap

0.020-0.024

Carburetor ID #

Dellorto PHBE 34 BD8

No. of Injectors

Three

Main Jet

165

Do Not Exceed RPM

6300

Idle Jet

Peak HP RPM

6000

Needle Jet

AB 265

HP @ Peak RPM

100

Needle Position

#1 Top

Peak Torque RPM

5500

Needle #

K43

Peak Torque Ft.Lb.

Float

8.5

Maximum CHT

390°F

Idle Screw

3/4 Turn Out

Maximum EGT @ full power

1150°F

Cold Start/ Choke Jet

Maximum EGT @ cruise power

1230°F

Maximum coolant temperature

220°F

Minimum coolant temperature

160°F

Form 16016 rev2

Crankshaft 3701

50*

Fig.

Qty.

Description

Neoteric

Remark / Notes

No.

Part #

Crankshaft

7167

Includes items 20 - 40

Deep grove ball bearing

7168

Deep grove ball bearing

7169

Shaft sealing ring

5453

Deep grove ball bearing

7170

* Connecting Rods are Color-Coded with a

Needle Bearing, Blue dot (#1)

7909

Paint Dot on the Piston end.

Engines built from 2010 onward also include

Needle Bearing, Yellow dot (#2)

6082

a Number Code next to the Paint Dot. The

coding corresponds to the correct Needle

bearing size. (Approx 0.0003" [0.008mm]

6083

graduation between each size)

Needle Bearing, Red dot (#3)

Blue (#1) is the smallest and Green (#5) is

the largest. Connecting rods with a Red (#3)

Needle Bearing, White dot (#4)

5464

dot are most common.

If the paint dot is missing and no number

Needle Bearing, Green dot (#5)

7910

code can be found, all bearings must be tried

for the best fit.

Form 17692 rev3

Cooling system 3701

Fig. No.

Quantity

Designation

Neoteric Part No

Inlet intermediate piece

7171

Inlet end piece

7172

Inlet intermediate piece

7173

Plug

7174

Hexagon head screw

6927

Loctite 242

Sealing ring, aluminum

5629

Cylinder screw

2292

Sealing joint Gasket

6095

Sealing joint Gasket

6095

Cylinder screw

6911

Loctite 242

100

Locking washer

6902

110

Coolant hose

7176

120

Hose clamp

6802

Water pump and housing

7178

Contains Pos. 130-

240

130

Water pump

7179

140

Sealing joint f. water pump

7180

150

Holder for water pump

7181

clamping

160

Cylinder screw

7182

Loctite 242

170

Washer

6936

180

Cylinder screw

7183

Loctite 242

190

Washer

6916

200

Washer

5996

210

Casing for water pump

7184

230

Hexagon head screw

6927

Loctite 242

240

Sealing ring, aluminum

5629

250

Stay bolt

7185

Loctite 242

255

Hexagon head nut

7186

Loctite 242

265

Hexagon head nut

6233

270

Washer

6162

Loctite 242

280

Water Pump Pulley

6645

280

Water Pump Pulley SS

7613

290

Cylinder screw

7189

300

Washer

6916

310

Driver Pulley

6646

see forms: 17458rev2

310

Driver Pulley SS

7612

and 16673rev2 bellow

320

Cylinder screw

7189

330

Locking washer

6902

340

V-Belt

6104

350

Coolant hose 90°

7190

360

Connection tube

7191

380

Water Temp Sender

6277

Form 17694 rev4

Hirth 100HP Ignition System

170

180

160

150

190

110

100

140

130

120

Fig.

Qty

Description

Neoteric

Remark /

No.

Part #

Notes

Grommet

7194

Not to Scale

Armature plate, complete

6564

Not to Scale

Cylinder screw

7182

Torque = 4 - 4.5 Nm (3 - 3.3 ft-lb) & Loctite 243

Washer

6936

Voltage Regulator

5338

Magnet flywheel, complete

7195

Not to Scale

Magnet support

5724

Cylinder Screw

6901

Lock Washer

6902

Plastic P-Clip

2192

100

Coil Bag

6705

110

100HP Ignition Coil

7053

Must be purchased as a set

120

Spark Plug Lead Set

7056

(contains black boots; not shown)

*No longer available; Must purchase set 7056

120

Spark Plug Lead, Old Style

7343*

(contains red boots as shown above)

130

Spark Plug

6187

140

Nylon Wire Tie

2372

150

100HP Modified CDI

7814

160

Hex Bolt

2230

170

Mount Plate Grommet

6806

No Longer Used

180

Outer Coil Mount Plate

5883

No Longer Used

190

Inner Coil Mount Plate

7197

No Longer Used

Form 17696 rev3

Carburetor (Dellorto) F 33 A (PHBE 34 BD 6832)

Fig.

Neoteric

Qty.

Description

Remark/Note

No.

Part #

Throttle slide

9022

Jet needle, K36

6563

Needle jet

Main jet

See Form # 17367 for all Dellorto Jets

Idle jet, 65

9023

Cold start / Choke jet

7788

Float valve

9024

Float

6909

Rubber cap

6113

*Included in 7828 Kit

Choke Cable Adjustment

7828

*Must Purchase 7828 Kit

Choke Cable Adjustment Locknut

7828

*Must Purchase 7828 Kit

Top Cover Screw

9027

Choke Support Screw

9028

*Must Purchase 7828 Kit

Choke Support Casting

9029

*Must Purchase 7828 Kit

Choke Support O-ring

7828

Included in Pos. 59

Choke Valve Spring

9030

*Must Purchase 7828 Kit

Choke valve

7828

*Must Purchase 7828 Kit

Throttle Slide Spring

9025

Bracket plate

6973

Top Cover O-Ring

9026

Included in Pos. 59

Mixture Adjustment Screw

9031

Mixture Adjustment Spring

9032

Mixture Adjustment Washer

9033

Mixture Adjustment O-ring

Included in pos. 59

Idle Adjustment Screw

9034

Idle Adjustment Spring

9035

Idle Adjustment Washer

9036

Idle Adjustment O-ring

Included in Pos. 59

Fuel Inlet Filter

9037

Fuel Inlet O-ring

Included in Pos. 59

Fuel Inlet Screw

9038

Needle Valve Gasket Washer

Included in Pos. 59

Cold Start / Choke O-ring

Included in Pos. 59

Main jet holding screw

9039

Float Pivot Pin

9040

Sealing for float chamber

9296

Included in Pos. 59

Float Bowl

9041

Float Bowl Gasket Washer

7213

Included in Pos. 59

Float Bowl Gasket O-Ring

2739

Optional Replacement For Washer

Float Bowl Nut

9042

Fuel Inlet Nipple

6114

Carburetor Top Cover

9043

Includes Pos.

Gasket set

5468

16,21,25,29,32,34,35,38,40

Form 17755 rev4

Hirth 65HP Fuel Injection / Fuel mixture

Fig.

Neoteric

Qty.

Description

Remark / Notes

No.

Part #

Reed valve

7203

Intake manifold

6568

Hose clamp

9008

Gasket

5463

Cylinder screw

2292

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

Washer

6916

Throttle manifold

5594

Clamp

6929

Cylinder screw

6901

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

100

Washer

6916

110

Washer

5996

120

Hexagon head nut

9009

130

Hexagon head nut, self.

5572

140

Ground cable

6454

150

Air filter

6622

6904

*Used up to May-2011

160

Fuel Injector, Old Style

(Engine #902754 & Lower)

6903

Currently used, from May-2011 onward

160

Fuel Injector, New Style

(Engine #902754 & Higher)

170

Injector Holding plate

9010

180

Washer

9011

190

Cylinder screw

9012

Loctite 243

7188

Shown in illustration;

200

Pressure regulator, Old Style

*Used up to May-2011

(Engine #902754 & Lower)

7932

200

Pressure regulator, New Style

Currently used, from May-2011 onward

(Engine #902754 & Higher)

200

Pressure regulator, Replacement

7279

Compatible with both old & new styles

210

Pressure regulator holder, complete

9013

220

Cylinder screw

7189

Torque = 9.6 - 11 Nm (7.1 - 8.1 ft-lb)

230

Washer

6916

240

Cylinder screw

9014

Loctite 243

250

Washer

6936

260

Hexagon head nut

9015

270

Washer

9016

280

Cylinder screw

9017

290

Washer

6936

300

Bushing

6935

Form 16022 rev3

Hirth 100HP Cylinder Parts List

Fig.

Qty

Description

Neoteric Part #

Remark note

No.

Cylinders Marked w/ Letter A, B, or C. If

no Letter it is a B cyl. Ensure to check

Cylinder

6090

cylinder & order proper replacement. Cyl

marked toward top, Letter is by itself.

Cylinder base gasket

5455

Hexagon head nut

6233

Washer

6234

Piston set

5450

Contains Fig. 51-55

Piston

7210

Piston Marke w/ Letter corresponding to

cylinder. A, B, or C. Marked on top of

piston.

Piston ring

5452

Piston ring

5451

Piston pin

5972

Circle clip

6301

Cylinder head

6089

Specify Single Ignition

O-Ring

5892

O-Ring

5893

Cylinder screw

6408

100

Washer

6407

110

Bleed screw

6409

120

Sealing ring

6410

Form 16622 rev2

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

Engine Troubleshooting & Maintenance

Engine problems

When an engine will not start, first check for spark. Pull the spark plug and connect it to the high

tension lead. Place the plug on the engine block and crank or pull the recoil starter and look for

spark. Sometimes in sunlight it is impossible to see the spark. It might be possible to hear the

spark and, lastly, if you get an electrical jolt then this confirms spark is present.

While the plug is removed, place a finger over the plug hole and crank the engine. Check for

compression. Lastly, check for fuel. Remove the air cleaner, open the throttle and squirt gas into

the cylinder. If the engine fires then stops, or runs only for a short time (1-2 seconds), this

indicates that the engine is not getting fuel. Check the tank level, primer, filter, fuel line and

quick connects, if installed. To pinpoint the problem, rig up a separate fuel supply directly to the

carburetor. If the engine runs properly, disconnect the temporary fuel supply and move along the

fuel line, changing components until the culprit is found.

The three fundamentals to check are spark, compression and fuel. Engines will not function if

any of these are missing. Always check the easiest things first. When there is no spark, check the

kill switch. Next, begin replacing components, coil, cdi and finally, remove the flywheel and

check the magneto.

Normal compression should be between 100 and 120 p.s.i. If compression is low, the engine will

be difficult to start. If no compression, the engine will have to be dismantled and repaired.

The fundamental rules for the mechanic are 1) Always check simple things first, and 2) Check

one thing at a time.

Engine adjustment

Modern materials limit the maximum power any engine can generate. Running an engine at the

maximum temperature, just below the melting point of its constituent materials, will produce the

maximum power. It’s in our interest to tune the engine so that full power is developed, yet the

engine does not melt.

Think of an engine as an oxyacetylene cutting torch. When more fuel (acetylene) is added, the

flame temperature drops but when more oxygen is added the temperature goes up. It’s exactly

the same with an engine.

Form: 17477

Oxygen varies depending on air temp and pressure. High altitude means low air pressure. Hot

weather means low oxygen. With varying oxygen, the fuel also must be adjusted or the engine

can melt. Fuel supply is regulated either by injectors, which are computer controlled, or by a

carburetor. When an engine runs with too much fuel it is said to be running rich. When there is

too little it is running lean. Of the two, running lean is the most dangerous. The engine will

develop more power but will be close to melting. Rich and lean have nothing to do with the

quantity of lubricating oil. Engines must have lubricating oil or they will seize. See Engine

Altitude and Air Temperature graphs in the engine Appendices at the back of this manual.

To check how an engine is running, look at the spark plug after the first half hour of operation.

The plug color must be chocolate. If black, this indicates the engine is running rich; the black is

unburned hydrocarbon. If grey, this is dangerous; it means the engine is about to melt. The grey

is ash from the oil/fuel and particles of aluminum off the piston which are depositing on the plug.

The engine is running lean.

In cold weather, i.e. below freezing or whenever engine icing occurs, the engine heat flap can be

untied and attached to the underside of the air filter box where Velcro strips are provided. This

directs heated air from the engine cylinders into the intake filters, which will correct the tendency

for engine icing to develop. This is only available on Fuji engine equipped Neoteric craft.

The Hirth engine produces hot air from its air cooling system, part of which flows over the

carburetors; this air is sufficient to prevent carburetor icing.

Form: 17477

Cautions

When replacing spark plugs, be sure that the plug is tight, but not too tight; it should be about 15

to 18 ft lbs. Coat threads with copper based anti-seize thread lubricant (Anti-Seize compound

sealing lubricant 765-1363 is suitable). A loose plug can lead to the cylinder head melting.

When mixing fuel for the engine, use proper 2-cycle oil, and use a good quality oil with a

reputable brand name; snowmobile oil is preferred; use NAMMA TC- W3. Do not use synthetic

oil. Mix 40:1, i.e. 16 oz of 2-cycle oil to 5 gallons (25ml oil to 1000 ml (1 liter) gas). Too much

oil can cause carbon buildup inside the cylinder head, piston walls, the rings and their grooves;

this can result in ring sticking followed by a subsequent loss of compression. The engine will

then become difficult to start and to keep running. It is advised to use high octane gasoline when

available; this lessens the possibility of pinging and pre- detonation.

Engine maintenance

Always mix gasoline and oil unless the engine is equipped with an oil injection system.

For oil injection engines, add oil 100:1 to gasoline until the oil delivery system can be

monitored for proper performance.

For the first 10 hours of new engine operation, restrict maximum power to the minimum

possible amount, no more than 10-15 seconds of full power bursts from time to time, and

try to run the engine for longer periods, such as ½ hour at 4000 rpm, then 3000 and 5000,

all for ½ hour intervals.

Mix gasoline (high octane is recommended) with North American Marine Manufacturers

Association Standard TCW3 2 cycle oil 40:1 and mark the portable fuel tank 40:1 with a

removable sign to prevent accident addition of gas without oil.

Engine idle should never exceed 1400 rpm. For 100 hp engines, minimum cranking speed

is 500 rpm.

Exhaust gas temperature should not exceed 1350° F, while cylinder head temperature

should remain below 535° F unless it is a liquid cooled engine, which runs at max 240° F,

min 160°F.

Do not over rev an engine; 6500 is tops.

The Hirth engine company recommends torqueing the cylinder and head bolts after the

first 10 hours, but this is immensely difficult. Where possible, these are checked by

Neoteric before engines are installed.

When the hovercraft has arrived at its place of use, check spark plug color after the first

½ hour test run. Make fuel mixture adjustments as required. Get the help of a snowmobile

or motor bike mechanic to help if you are unsure of this task.

Always examine an engine for oil leaks and investigate such leaks whenever they are

found.

10. Always wash the engine with fresh water after operating, then spray down with kerosene,

WD40 or light machine oil. This will prevent corrosion and is especially important for

salt water operation.

11. Whenever operating in a dusty region, remove engine air filters and clean in accordance

with instructions found elsewhere in the manual.

12. Always inspect engine for cracks, loose bolts or fittings and check all belts for proper

tension. Correct when needed.

Form: 17477

13. Do not crank engine excessively. If it does not fire within 5-10 seconds, something is

wrong. Check that the kill switch is engaged. Remove plugs and clean excessive oil.

Replace plugs and restart.

14. Injectors can be used to prime the cylinder. Open throttle ¾ of a turn and you will hear

the injectors buzz.

15. Always inspect cooling systems and radiators; clear debris and make sure coolant level is

sufficient. Also check pump belt.

16. Ensure there are no loose wires, especially battery terminals and engine ground wire.

17. When checking the engine for problems, endeavor to make one change at a time then

check before making any additional changes.

18. To test fuel injected engines, a laptop program must be obtained from Hirth. The

computer chip can be changed with different mapping.

19. Engine shut down temperature for air cooled engines should be under 300° F. cylinder

head temp.

20. Always turn injected engines on and off using the fuel pump switch. Turn key on, then

turn fuel pump switch to on and listen for fuel pump. Use the key to start the engine. To

stop the engine, turn the fuel pump off first in order to depressurize the fuel system and

stop the engine. Then turn the key off. The fuel pump can take up to 5 seconds to prime.

Most hovercraft are equipped with some form of primer bulb needed to re-prime the fuel

pump whenever fuel line air blockage occurs.

Form: 17477

Craft Service & Maintenance

Neoteric Hovertrek™ lubrication

Fan shaft bearings:

After every 25 hours, lubricate each fan shaft bearing with regular wheel bearing grease. Do not

overgrease and damage bearing seals.

Control bearings:

Using SAE 30 oil, lubricate all rudder blade bearings, clevises, pins and rudder push pull cable.

Torsion steering post:

Lubricate reverse thrust cable drums, BMW reverse thrust levers and cables, throttle cables, seat

sliding and rolling parts on SxS craft with SAE 30 oil.

Engine:

Choose an oil with a National Marine Manufacturers Association (NMMA) TC-W3 or similar

standard 2 cycle engine oil and mix 40:1 with 95 octane gasoline.

40 Gas

:1 Oil

1 US gallon

(=3785 ml):

0.025 US gallon (=95ml)

8 US pints

(=1 US gal):

0.2 US pints

128 fluid oz

(=1 US gal):

3.2 fluid oz

Trailer:

Check and repack wheel bearings after 1000 miles. Lubricate winch with SAE 30 oil. Lubricate

ball hitch with SAE 30 oil.

Form: 17477

Neoteric Hovertrek™ electrical fuses

Reverse thrust system :

could be round tube fuse or blade fuse 15 amp

Reverse thrust computer:

round tube fuses or blade 5 amp/computer (watertight holder;

only models prior to 2008), new digital computer

Navigation lights, headlights, instrument lights:

20 amp blade f u s e ( f o r C o n v e n t i o n a l R e s i s t a n c e

Light) 10 amp for current LED light.

Bilge pump and horn:

10 amp

Siren:

Current model: 20 amp blade built inside at back (Prior to

2006: outside at back.

Strobe or rotating light bar:

10 amp

Gauges:

10 amp

GPS:

Self-equipped fuse

Searchlight:

15 amp

Cigarette lighter plug and deck plug:

10 amp

Volt regulator:

30 amp

Side lights:

15 amp

Injected engine computer:

15 amp

Marine radio:

250 volt/6 amp

Skirt repairs

Replace segments when worn or damaged. Operating your Neoteric Hovertrek™ with holes and

tears in the skirt can be dangerous and is not recommended. If skirt damage is extensive, replace

the entire skirt. With care and good operating procedures a skirt should last for 120 hours. Even

under normal conditions, skirts take a great deal of punishment and might wear badly in as little

as 25 hours. Damage is usually erosion, which is confined to the lower edges of the skirt. Wear

patches can be inexpensively stitched over the worn area; use 16 oz. Neoprene Coated Nylon

truck tarpaulin material, but any fabric material at hand will work, such as 7oz/sq yd nylon pack

cloth. When one or more segments are torn, be sure to make speedy replacement since each

damaged segment lowers the hoverheight slightly. This then increases the surface contact of all

the skirts so that they will all wear more rapidly.

Major fan and transmission repairs

Remove fan intake screen.

Disconnect fuel supply.

Remove all electrical connections, mark each wire with a number and take note

of connection. Wires will have to be cut. Mark all cut wires for identification

during reassembly.

Remove choke and throttle cables.

Undo bolts holding engine mount feet to vibration mounts. Collect spacers and

label their location.

Remove thrust duct using a screwdriver. Remove or loosen set screw above fan

hub key. This might be a square head set screw which is easy to remove. If it is

Form: 17477

an Allen head set screw this is more difficult to loosen. Apply heat with a

propane torch to the fan taper lock and concentrate around the set screw area as

that will soften the Loctite.

Remove the three 5/16 hex head bolts holding the taper lock bushing. Place two

of these bolts in the threaded holes in the taper lock flange and tighten until the

taper lock bushing separates. A wheel puller is needed to remove the taper lock

off the fan shaft. Then the fan will come off.

To remove the fan shaft: clean off any paint or corrosion on the fan

shaft. Loosen the bearing clamps and tap the shaft through the bearings while

spraying the shaft with WD40. Use a soft Aluminum or copper drift to force the

shaft out through the bearings. Remove the large drive sprocket by loosening the

small Socket Head screws on the B Lock assembly holding the sprocket to the

shaft. Remove the belt. Remove the 3 Hex head bolts holding the Belt Sheave

and loosen all engine mount bolts. Remove the bolt shims between the engine

and the engine mount in order to loosen the belt. Start with the shims under the

engine bolts closest to the front of the craft. Make sure to keep the shims together

and when reassembling, the exact same shims must go back under the exact same

engine bolt.

Return the shaft and the complete fan to Neoteric with the taper lock for

balancing the assembly after repairing.

Remove the foam vibration isolation strip; it might have to be cut off.

Undo the eight 7/16 hex stainless steel bolts holding the thrust shroud. Force

the shroud back.

Tilt machinery module forward and remove from craft.

In operation, check belt adjustment; belt should run very slightly to the front of

the craft. This is achieved with slightly thicker shims under the engine mounts

toward the rear of the craft.

Fan blades can be replaced through the opening created by removing the thrust

duct. Work on fan blades is more easily achieved by removing the fan to the

workbench. Take fan taper lock bolts out and screw them into threaded holes

on taper lock. Tighten until taper is broken and fan is removed using a wheel

puller and heat.

To remove engine drive sprocket, undo sheave bolts, remove belt sheave

flange, fit puller and tension, then heat evenly using propane or oxy-acetylene

flame until sprocket breaks loose.

Re-assembly:

Torque fan taper lock to 12 ft lb.

Torque sprocket locking hub to 7.5 ft lb.

Torque engine bolts to 55 ft lb.

Torque drive sprocket to 65 ft lb.

Torque bearing bolts to 65 ft lb.

Torque bearing lock collar 6 ft lb.

Torque engine intake manifold boots 6.6 ft lb.

Form: 17477

Repairs to controls

Rudders: Rudder blades can be replaced using a Phillips screwdriver. In

operation the rudders should move + or - 32 degrees.

Reverse Thrust Buckets: Reverse thrust bucket bearings should be replaced

when worn. If fiberglass body is damages around plastic bucket bearing hole, re-

glass before installing new bearings. Hovercraft manufactured after 2003 have

bearings built into the body so maintenance should not be needed except for

lubrication or repair.

Computer Controlled Reversers: The fly by wire computer operated reverse

thrust system consists of three components: two hand operated

10-ohm

potentiometers, a computer, and two electrical actuators. The hand-operated

potentiometer provides a voltage signal to the computer. A

10K-ohm

potentiometer inside the actuator tells the computer the position of the actuator.

The actuator position is then compared by the computer to the hand- operated

potentiometer. If they are different +/- 12 volts DC is sent to the actuator, which

moves until the signals are balanced. A 12-volt clutch in the actuator remains

engages while there is a power supply to the system.

Hand operated potentiometer specification are: 10K ohm, sealed, 280 degrees of

rotation potentiometer, stainless steel shaft and resistance coil type.

Form: 17477

Reverse Thrust System

Description

Microprocessor-based position controller, driving 2 linear actuators based upon two

potentiometer inputs, providing diagnostics and field calibration

Hardware specifications

Operating Ambient:

-30F to 120F

Construction:

6.75” x 5.0” circuit board to match - provided enclosure (mounted

inside port thrust duct)

Power Terminal Blocks:

Screw-type terminal blocks, 14-22 AWG.

Over-current Adjustment:

3A to 15A amps, on-board potentiometer.

Actuator Outputs:

Two bi-directional, solid-state MOSFET, 15 amp max

Actuator Inputs:

Two 10K potentiometers

Actuator Terminal Blocks:

Screw-type terminal blocks, 14 - 22 AWG

Hand-lever Input:

Two 10K potentiometers

Diagnostic LED Outputs:

Two, rated +12 VDC, 40m A maximum

Calibration Switch Input:

Momentary switch closure, rated +12V, 25mA minimum

Hand-lever Terminal Blocks: Screw-type terminal blocks, 14 - 22 AWG

Software specifications

Auto-Calibrate Mode:

Both hand levers must be in the released position. The buckets can be in any position.

This mode is entered within 15 seconds of powering up the computer then pressing and releasing

the momentary switch on the instrument panel. After 15 seconds, the calibration mode cannot be

entered.

During the 15 second period, the hand levers will not directly control the actuators.

Both LED’s on the instrument panel will flash rapidly.

The pilot then fully engages each hand lever and holds for 3 seconds, then fully releases each

hand lever. Each actuator will run to the fully retracted and fully extended positions.

The potentiometer values of all four points will be recorded automatically and stored in memory.

When the auto-calibrate mode has been completed, the LED’s will be steady and the pilot will

regain control of the actuators.

Typically, the entire period of operation will be completed in less than 30 seconds.

User mode

Based on the stored potentiometer values from the auto-calibrate period, the software will equate a

hand lever potentiometer value to an actuator potentiometer value by running the actuator motor.

This will be a linear relationship. For example, if the hand levers are retracted 50% of the total

distance, the actuator will extend to 50% of the total distance.

The control will shut down if the actuator motor is running and the control senses a current

greater than the over-current adjustment (see hardware spec) for a time set by the dip switch (see

Option Switches section).

Each time the bucket is fully extended or fully retracted, this position will be compared with the

position stored during the auto-calibrate period. If these values are the same, the control

continues to operate normally. If the bucket is unable to reach the calibrated position, due to an

obstruction, the motor will shut off after 3 or 5 seconds depending on the dip switch setting, and

the LED will display an error code (see Diagnostics).

Each time the pilot moves the hand levers, the control will try to move the bucket to the

calibrated position.

Diagnostics

The two instrument panel LEDs will be on when there are no faults. When there is a fault, the

LED will flash a number of times, corresponding to the following error code. Each LED operates

independently.

1 flash

= Bucket can’t fully open.

2 flashes

= Bucket can’t fully close (reverse).

3 flashes

= Actuator potentiometer failure, ohmic value out of range.

4 flashes

= Bucket not able to reach correct position per hand lever.

5 flashes

= Hand lever potentiometer failure, ohmic value out of range.

6 flashes

= Recalibration required.

7 flashes

= Cycle power off and on; calibration error.

Option switches

Switch

Switch set to “open” side

Switch set to “number” side

Actuator motors run 100%

Actuator motors run 80% of full speed

Over-current timeout = 3 seconds

Over-current timeout = 5 seconds

Hand-levers dampened 2% of range

Hand-levers dampened 4% of range

Disable ramping actuator speed

Enable ramping when motor at full

speed

Electrical actuator specifications

Volts:

+ / - 12 volts nominal

Load:

30 lbs. @ 3 amp

Peak load, Momentary:

60 lbs.

Motor current (at rated load):

2.25 amps

Motor locked rotor current:

18 amps

Clutch current:

0.6 amps

Stroke (max)

3 inches

Maximum no load speed:

3 inches/second

Weight:

2.4 lbs.

Operating temp Range:

-40°F (-40°C) to + 158°F (70°C)

Operating voltage range:

+/- 11.5 to 16.0 Vdc

NOTE: If voltage drops below 12 Vdc, actuator will continue to operate at a decreased

performance level.

Construction:

• Aluminum die cast housing

• Powder-coated for corrosion resistance

• Permanently lubricated metal gear drive

• Stainless steel output shaft

• Sealed construction

• Dust proof and splash proof

• Polypak rod seal

• 4-start stainless steel Acme screw 7-wire, 20 gauge,

shielded cable, 3 feet long

Installing reverse thrust potentiometer controls

Fit potentiometer (pot.) to bracket with shaft pointing through the bottom of the bracket in the

same direction as the welded ends.

Turn the pot. fully clockwise then back 10º and place the cable drum on the pot. shaft so that the

slot is parallel with the edges of the bracket and the rounded sides of the slot are facing away

from the side of the bracket through which the cable passes. The small set screw is now on the

left side with the cable just passing over the top edge of the set screw. The top of the pot. shaft

should line up with the bottom of the drum cable slot. Tighten 3/16 set screw.

Fit the brass end of the cable to the BMW control lever (take note of the arrangement of parts if

you start this procedure by dismantling these controls). Fit the cable-housing end into the cable

receptor on the bracket. Turn drum and pot. 10º or so counterclockwise. Wrap cable with loop

end about 260º clockwise around drum; feed through slot so that the cable bend takes place in the

carved out slot. Wrap remainder of cable, tighten about 280º clockwise around drum and fit

spring through loop in cable. Stretch spring and hook its other end through the hole provided in

the bracket. Fit 5/16 set screw and tighten down on cable with a pinching force. Operate BMW

bucket levers while checking for proper rotation of pot. drum. If cable rubs against itself, rotate

spring until rubbing stops. Drum must rotate a total of about 100º. Lubricate cable with SAE 30

oil.

Testing actuator

First, disconnect actuator cable from computer.

Connect 12 Vdc to the red and black actuator wires. Measure the current; this should be 0.6

amps. If not 0.6, actuator is faulty. Reverse the 12 Vdc to black and red wires and check for 0.6

amps.

Connect 12 Vdc positive to blue and negative (ground) to green actuator wires. Clutch should

engage and hold actuator rod from moving. If rod can be moved clutch is damaged.

Attach an ohmmeter to the brown and orange wires, which are connected to the potentiometer

inside the actuator. A reading of 8 - 12 K ohms should be obtained otherwise internal

potentiometer is defective.

Attach ohmmeter to brown and white wires. Move the actuator full stroke. The ohmmeter should

read 0 -10 K ohms. If the ohmmeter shows any discontinuity, peeks or 0 ohms during the stroke,

the potentiometer is faulty.

Hand control potentiometer: This should read 0 - 10 K ohms when tested.

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

31^st Jan 2020

REVERSE THRUST COMPUTER BOARD TEST PROCEDURE

By Dave Xiang

Nomenclature:

Square wave: Any signal on an oscilloscope that has a high for a certain time and low for a certain

time. The duty cycle is not exactly 50% but pretty close to it.

PWM: Pulse Width Modulation (PWM) indicates a signal on an oscilloscope that has a high for a

certain time and low for a certain time. The duty cycle is not 50%.

Main chip: The main chip is the largest chip on the computer board, it is the core chip on the board.

Power switch: Is an on/off switch on the instrument panel. Toggle the switch to ON position to give

power to the reverse thrust computer board and actuators.

Calibration switch: Is a momentary switch on the instrument panel. Flipping the switch up within 30

seconds of system bootup will result in the system entering calibration mode. Calibration procedure is

performed by turning the power switch on, followed by the calibration switch activation then hold the

reverse handlevers 100% on for 3 seconds before releasing.

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

The main chip

Abstract:

The most common problem on the Neoteric reverse thrust computer is the failure of MOSFETs.

In such situations, the actuator cannot work. Replacing a pair of MOSFETs usually solves the

problem. Other problems include: unable to save calibration data, LED malfunctioning and

unable to read potentiometer, replacing the related component can sometimes fix the

problem.

Equipment:

1: 12V power supply

2: Oscillscope: Recommended an oscilloscope with at least 2 channels.

3: Digital multimeter: Usually used to test continuity. It could also be used to test input voltage.

4: Zip tags: zip tags can be useful when testing the handle bar potentiometers.

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

2: If 12V and ground are connected, check C1 and reg1-A. The problem could be in the DC to DC power

converter. It may take several trials to verify un-connectivity because of the circuit protection. If 12V

and ground are still connected after several trials, test reg1-A. To test reg1-A, measure the continuity

using a multimeter between 12V, and plus side of C2. Normally, they would not be connected. They

usually burn when failed. Replace reg1-A to solve the problem.

12V

REG1-A

3: Test the board by connecting 12V and GND. Flip the power switch and see if the LED on the computer

board is blinking. If not, measure output on the 24^th pin on IC1 during calibration using an oscilloscope. If

there is no square wave pattern, the main chip is gone. Replace the computer board.

LED

Connect 12V and GND

IC1

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

4: Further, connect the wires on the 8 pin connector. The wire color for the bottom right section from

TOP to BOTTOM should be black (Negative of handgrip potentiometer), red

(plus of handgrip

potentiometer), green

(middle port of port potentiometer), white

(middle port of starboard

potentiometer), red (calibration switch), white (port LED), black (starboard LED). (Reverse in any of the

wires may damage components on the computer board). Perform calibration. If the two LEDs on the

intrument panel blink for a while then stop, go to step 7. If not blinking, first check LED(s) by measuring

the voltage between the white wire (port LED) to GND and the black wire (starboard LED) to GND during

calibration using a multimeter or oscilloscope. If you see a square wave on the oscilloscope or get a

value between 12 and 0V on a multimeter, the LED is broken. Replace the related LED. If you do not see

a square wave or the voltage is 0V, go to step 5.

From top to bottom:

Black: Negative of handgrip potentiometer

Red: Plus of handgrip potentiometer

Green: Middle port of port potentiometer

White: Middle port of starboard potentiometer

Red: Calibration switch

White: Port LED

Black: Starboard LED

5: Check ISO1 (the white 6 pin chip), pin 1 of ISO 1 should be around 12V when calibration switch is held

on, and pin 5 of ISO1 should be close to 5V. Use an oscilloscope in this test. ISO1 functions as a bridge

that changes the 12V signal from the calibration switch to 5V going to the main chip. Replace the ISO1

when the voltage is not correct. The component name for ISO1 is 4N35. It could be found at Digikey and

other places that sell electrical components. Notice that if any voltage higher than 7V on pin 5, the main

chip may have failed.

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

ISO1

6: Check IC4 (black 16pin chip) use the following method: Check the connectivity between pin 1 and pin

8 using multimeter when both switches are off. They are usually connected when there is a problem. To

continue checking, put two probes of oscilloscope on the following pair of pins (7&10, 8&11) while

calibrating and look at the waveform. It should show an opposite wave form (if one voltage is high,

another should be low at the same time). If the waveform is not present in pin 10 & 11, IC4 has a

problem, replace IC4 (It is a ULN2003A chip). If No wave form on both sides, the main chip is gone.

Replace the computer board.

IC4

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

7: To test the actuator driver, connect 12V and GND to the terminal circled on the next figure. Ground

is in the middle and 12V is on the side. Leave the actuator disconnected. Measure the connectivity of

12V and ground using a multimeter. If there is continuity, at least one pair of the MOSFET has failed, go

to step 11. If they are not connected, go to step 8

Connect the circled wire, 12V on the side,

GND in the middle

Connect the circled wire, 12V on the

top, GND on the bottom

8: Flip the power on. Measure the following voltage of each port in TB3 and TB4. An oscilloscope is

preferred in this test. Pin 5 (blue) should be 12V, Pin 6 & 7 (green and bare) should be ground. Pin 8

(orange) should be 5V and Pin 10 (brown) should be ground. If any of the voltage is not seen, first

check if there are any broken traces on the circuit computer board. Then go back to step 2. REG-1A

may have to be replaced.

10,9,8,7,6,5,4,3,2,1

1,2,3,4,5,6,7,8,9,10

TB3

TB4

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

9: Put one oscilloscope probe on Pin 3 (red) and one on Pin 4 (black), perform calibration. Wait for a

short period, two Pulse Width Modulation waveform (PWM) should appear on the oscilloscope. As

indicated by the following picture. If any one of the signals is not present, check IC4 (in step 6) and

MOSFETs (step 10). Otherwise, go to step 12

(image achieved by attached channel 1 to Pin 3 of TB3 channel 2 to Pin 4 of TB3)

This step could also be done by using two multimeters. Switch them to measure 20V DC. Put the black

lead on multimeter on any of the ground Pin 1 on TB3 or TB4. Put one of the red lead multimeters on Pin

3, and one on Pin 4. You should see one of the multimeters go high (lager than 8V) and then low (less

than 5V), as one multimeter goes low, the other multimeter should go high. If any one of the signals is

not presented, check IC4 (in step 6) and MOSFETs (step 10). Otherwise, go to step 11.

Form: 17478

Neoteric

Hovercraft Inc.

1649 Tippecanoe Street • Terre Haute, Indiana, USA 47807-2394

TELEPHONE: 812-234-1120 • 800-285-3761 • FAX: 877-640-8507

EMAIL: Hovermail@NeotericHovercraft.com • WEB: NeotericHovercraft.com • RescueHovercraft.com

10: Check MOSFETs: There are four pairs of MOSFETs on the reverse computer board. Each pair consist

of an N-channel and a P-channel MOSFET. It is a H bridge motor drive with some circuit protection. The

simplified structure is the following:

10,9,8,7,6,5, 4, 3,2,1

1,2,3,

4, 5, 6, 7, 8, 9,10

MOSFET Pairs

Usually, the bad pair of MOSFET would not give the waveform as indicated in the oscilloscope figure.

Check if there are any burn marks or black traces around MOSFET(s) to locate the problem. Use a

multimeter to measure the connectivity to trace which pair of MOSFETs has failed. If any MOSFET goes

wrong, two of three legs would be connected. MOSFET 1,2 are a pair, MOSFET 3,4 are a pair, MOSFET

5,6 are a pair, MOSFET 7,8 are a pair. When replacing MOSFETs, it is IMPORTANT to replace both. Do

NOT replace one in the pair, because the broken one can break the other. Those MOSFETs are P-channel

IRF9540N and N-channel IRF540N. Those two MOSFETs have exactly the same appearance, READ THE

MOSFET NAME TO MAKE SURE WHICH IS WHICH. Reversing the order would burn both MOSFETs.

11: If there is no problem in the pervious steps, connect the actuator. Connect both actuators on the

computer board and start testing the whole system. Turn the power on to see LED on the computer

board is blinking. Flip the calibration switch, and hold the handlevers for 3 seconds. See rods on actuator

extended to the maximum and then to the minimum. Then go roughly to the middle according to the

position of the two handlevers. After that, the two actuators can be controled by using the two

handlevers.

Form: 17478

General description of the fuel injection

The applied fuel injection system is a

sequential multipoint fuel injection. The throttle body injection is

installed instead of the carburetor. Both throttle body injection (TBI) units are connected at the bell

crank and are synchronized with each other through the throttle body shaft.

The fuel pressure is 42 Lbs. PSI. This is produced through an electric fuel pump and

stays consistent

with the help of a pressure regulator.

. Min voltage is 10v.

To avoid interruption from contaminated fuel, a series of fuel filters are installed fore and aft of the fuel

pump.

The amount of fuel is controlled through the injector nozzle (governed by the throttle position/RPM}.

The dosage is refined through different adjustment parameters.

The following parameters are used for the calculation of fuel ratio-amount of injection:

• Throttle position

• RPM

• Ambient air temperature

• Barometric pressure

• Engine crankcase temperature

• Acceleration rate

• Manual manipulation (optional)

Position # Description

Throttle cable tension adjustment stop nut

Throttle cable tension adjustment

Throttle stop plate

Synchronization adjustment screw (do not change)

Idle stop adjustment screw

Throttle bell crank

Assy 17309 Form 17117

Hirth US Distributor, RPE, Matt Dander Feb 2020

How to determine if Fuel Injection tach signal is working.

In order for the fuel injectors to activate at the correct time the Fuel Injection Computer, ECU needs

to know the RPM of the engine. This information is delivered from the CDI box(s) as a tach pulse.

Each CDI box(s) has a green wire that carries the tach signal. Both green wires on dual ignition

engines are connected to a yellow wire from the fuel injection wiring harness. This yellow wire

delivers the tach signal to the ECU. If the tach signal is never received from the CDI box(s) the

ECU does not know the engine is turning and does not deliver any fuel. To find out if there is a

missing tach signal turn on the power to the ECU, then advance the throttle to 65% open. A buzzing

noise coming from the injectors should be heard.

Every time the throttle goes from idle to past 65% open, the ECU turns all injectors to full power

for 1 second. The injectors rattle making the buzzing sound and a quantity of fuel is shot into the

engine. Return the throttle to about 20% and turn the engine over with the starter

(put ignition switch(s) in run position). The injected fuel will make the engine run for about 2

seconds and then stop. This test proves that the ECU is receiving power and working, the engine

ignition system is working but the ECU is not getting the tach signal, if it were the engine would

continue to run. If the tach signal is the problem then track down why. As mentioned above the

circuit from the 2 green wires from the CDI box(s) to the yellow wire in the ECU plug must be

complete. If the yellow wire is broken then the signal can not get through. If the wire is OK but the

terminal in the ECU plug is corroded the signal can not get through. If after inspection the tach

signal wiring turns out to be sound then 2 other possibilities exist.

The reason both green wires from the CDI(s) are attached to the yellow wire is for redundancy. If

one of the ignition system fails on dual ignition systems the tach signal from the remaining ignition

system keeps the engine running. In rare cases a CDI can go to ground internally and ground out the

tach signal. Since it is wired directly to the other CDI it can also ground out the signal of the other

CDI that is still working properly. To determine if a bad CDI is the problem separate the green

wires. Break the splice where the 2 green wires come together and attach only one to the yellow

wire from the wiring harness. Make the injectors buzz again, pull throttle to 20% and crank. If the

engine now continues to run then the connected CDI is bad. If it will not stay running switch the

yellow wire to the green wire from the other CDI and repeat the test. Can only do this on dual

injection systems. If the engine now continues to run the CDI tested previously is bad. If a bad CDI

turns out to be the culprit replace it and wire it as previously. If both tests fail to reveal a bad CDI

then the problem is in the ECU.

When the yellow wire delivers the tach signal to the ECU it is read with an input device within the

ECU. This device in turn sends the tach signal to an internal processor. If the input device should

fail the signal does not get through. If the wiring is good and that both CDI's are good then the only

thing left is the ECU. To confirm plug in another ECU that is known to be good and start the

engine. If the engine runs then the original ECU must be bad. Obtain a new ECU to perform this

test or send the suspect ECU in to the Hirth repair center to have it tested. After testing proves it bad

it can be repaired or a new ECU is purchased but at least by having it tested the next step is obvious.

Form: 16556

Appendix B

0-1

Appendix B

Additional Information for Engines with Oil Injection

Attention: The chapter on Oil Injection (Appendix B) is only to be used in connection

with the service manual for the corresponding engine type. All sections of

the manual, with exception of the chapters concerning lubrication, are

from here on still fully valid. Please read all instructions before installing

the engine or its operation.

General Directions:

In order to provide for the continuing further development of our products we have to reserve

the right to make changes in the size of deliveries, in form, technical execution, and

equipment. We also ask for your understanding that no claims can be made based on

information contained in this manual.

Göbler-Hirth Engines KG, Max-Eyth-Str. 10, 71726 Benningen, Germany

16.02.05

DOC_Anhang_B_E_0.01

Page 1 of 12

Appendix B

0-1

Description of Oil Injection

1.1

General description of oil injection

An oil pump transports the two stroke oil directly from a container into the intake manifold

and in special constructions also directly to hard to reach areas to be lubricated (for example:

top bearing when vertically installed [H30; H32]).

The oil pump is fastened to the recoil starter or to a support of the fan housing and is

connected by way of the clutch directly to the crankshaft.

With the exception of the H30, H37 and the H32, the oil ratio depends on 2 variables.

1. Number of rotations

2. Throttle position (loaded condition)

The oil ratio of the H30, H37 and the H32 depends solely on the engine rpm.

1.2

Names and description of individual parts

•

Oil container (sketch 5.1 pos. 5)

Function:

Reservoir for the two stroke oil for the oil injection

Minimum amount of oil:

F30, H30, 3701 und H37 > 2,5 Liter

All others > 1,5 Liter

1. Filling socket with air vent

2. Connection of oil line to oil pump

•

Oil level indicator and/or warning light (sketch 5.1. pos. 4)

Function: Gives information about present oil level and/or warns when below

minimum level.

•

Oil filter (sketch 5.1. pos. 3)

Function:

Cleaning the oil from foreign parts which may damage or conjest the oil

injection system.

•

Oil pump (sketch 5.1. pos. 2)

Function:

To dispatch and measure out the oil for the suction sockets and the areas

to be lubricated.

The oil pump consists of the following main components:

1. Rope disc and Bowden cable holder (pict. 1)

Function: Guide for load depending regulator for the amount of oil

Note:

With motors of the H-series the amount of oil will only be changed in

connection with the rotation number. Therefore, the lever has been adjusted and set

at the factory and may not be changed.

2. Oil connections (pict. 1)

Function: The connection from oil pump to motor has been factory-installed. The

open oil connector is for the connection from the oil reservoir.

16.02.05

DOC_Anhang_B_E_0.01

Page 3 of 12

Appendix B

0-1

2. Installation Instructions

The following instructions have to be adhered to for a safe and trouble free operation

2.1. Mechanical Installation (oil pump control):

• Install a "splitter" into the throttle cable for the carburettor - i.e. throttle valve control.

• Install a Bowden cable between splitter and oil pump.

• Measure and cut the end of Bowden cable and affix lead seal.

• Hang Bowden cable into guide disc.

For 2-cylinder engines:

• Open carburettor i.e. throttle valve completely and adjust the Bowden cable to the

required length (pict. 1a).

Attention:

please note that the respective marks on control dial of oil pump are to

be understood only as the minimum settings requiring the final

adjustment to the desired mixture ratio.

Remarks:

For engines with

2 carburettors or throttle valve sockets, the

carburettors, i.e. throttle valves first have to be synchronized to each

other, before adjusting the oil pump.

For 3-cylinder engines:

• keep the basic engine setting from factory or adjust the engine without load

(e.g.

propeller) to idle speed 1400-1500 rpm

Stop the engine and keep position of throttle valve in idle position.

Harmonize mark on oil pump housing and line mark on sheave.

In general:

• Secure the adjusting screw with counter nut.

• Activate throttle control several times, then check the adjustment and if necessary

readjust. Repeat until the setting does not change anymore.

• Check that the Bowden cable to the oil pump action is not bent and runs smoothly.

Furthermore, assure that the Bowden cable can not be damaged by sharp edges or nearby

heat, etc.

• Check that the Bowden cable can not jump from the guide disc.

Note:

The amount of oil may not be reduced by changing the setting of the guide

disc, because too lean an operation in the partial load may cause serious engine

damage. There is no way the operator can adjust the amount of oil.

2.2. Hydraulic Installation:

• The oil reservoir must be situated higher than the oil pump, since the oil pump can not

begin suction independently.

• An oil filter has to be installed between the oil reservoir and the oil pump in order to avoid

damage or clogging of the oil pump.

• All lines have to be attached in sufficient distance to hot parts (i.e. exhaust system).

• The oil lines have to be laid out in such a way, that they may not be damaged by sharp

edges.

• The oil lines must not be bent. They have to be secured in such a way that bending can not

occur even during operation.

• For safety, hose clamps must be affixed to all connections of the oil lines.

16.02.05

DOC_Anhang_B_E_0.01

Page 4 of 12

Appendix B

0-1

2.3. Installation Instruction

1. Mount the engine as described in the individual service manual.

2. Mount the oil reservoir as described in section 2.2 above.

3. Connect oil reservoir and oil pump, insert an oil filter into the line.

4. Ensure that the necessary amount of oil can flow from the oil reservoir to the oil pump.

To do this, hang the oil hose into a measuring cup at the level of the pump, fill 200 ml

2 stroke oil for the oil injection into the oil reservoir. Clock the time between the

beginning and the end of the oil flow.

5. For engines H30, F30, 3701, the 200ml must have run through a maximum of 20 min.

For engines 2702-2706 and H32 E, 30 min maximum. When measuring, the oil- and

surrounding temperature should be between 10-20°C. Should the passage take longer

than stated, the position of the oil reservoir has to be changed accordingly until the

flow condition described is reached.

6. Connect the oil hose to the entrance of the oil pump and secure with a hose clamp.

7. Fill oil reservoir with 2 stroke oil for the oil injection.

8. Vent the oil pump by opening the air vent screw (pictures 1a and 1b). Wait until the

oil exits the bore hole without bubbles. Then the vent bore hole must be closed again.

16.02.05

DOC_Anhang_B_E_0.01

Page 5 of 12

Appendix B

0-1

Picture 1b: Front view of oil pump (3-cylinder engines)

Air vent screw

Idle mark 3 cyl.

Oil exits

Marking oil pump

oil entrance

case

2.4 Additional Measures to Ensure Safety of the Construction:

The following measures are not necessary for a secure operation of the installation.

1. Install a fill level indicator into the oil reservoir to control the oil level.

2. Install a warning light when going under the minimum amount of oil.

Recommendation: The setting for the minimum amount of oil should be chosen so

as to ensure that the remaining amount of oil is sufficient for the

entire fuel tank capacity.

3. Check the used amount of oil in relationship to the used amount of fuel in order to be

able to react in time to a blocked or worn out oil pump.

Note:

The consumption of oil is strongly influenced by the fuel setting. If the

engine is operated with various loads the oil consumption may vary

also.

3. Operation of the System

3.1. Operational means

Only brand name 2 stroke oils may be used. They have to be suitable for oil injection

and must be labeled accordingly.

For safe engine operation and least wear Göbler-Hirth Engines recommends

BlueMax AL 2-stroke oil.

16.02.05

DOC_Anhang_B_E_0.01

Page 7 of 12

Appendix B

0-1

3.2. First Time Operation:

1. Fill fuel tank with at least 10 liters of pre mixed fuel (1:50).

2. Start engine and let idle.

3. Manually completely open guide disc of the oil pump (see picture 1).

4. Check that oil lines fill evenly with oil.

5. After all oil lines have filled with oil, reposition guide disc to the idle position.

6. Let engine run for another 5-10 minutes and turn off.

7. Check all oil lines for leaks and whether the oil pump setting is still correctly

adjusted.

8. Operate engine with the rest of the mixture, before refuelling.

3.3. Operation of the Oil Injection System:

See chapter 4 about maintenance and service intervals.

Before each operation it is necessary to ensure, that the oil reservoir contains a

sufficient amount of oil for the planned time of operation, since an interruption of the

oil supply may lead to serious engine damage.

16.02.05

DOC_Anhang_B_E_0.01

Page 8 of 12

Appendix B

0-1

6. Trouble Shooting

Attention, should it become clear that no or too little oil is being moved, the engine must immediately be changed to a

lubrication mixture of 1:50 until the problem is solved, otherwise serious damage to the engine may occur.

Problem

Cause

Control

Elimination

Insufficient oil flow

Oil pump setting not properly

See Chapter 2.1.

Readjust oil pump setting

adjusted

Oil filter blocked

Check amount of flow (see Chapter 2.3. Pos.5)

Exchange filter

Too much oil flow

Oil pump setting not properly

See Chapter 2.1

Read just pump setting

adjusted

No or too small amount of

Defektive injection valve

Exchange injection valves and check whether or not the defect

Replace injection valve

oil in one channel

changes too.

Oil line blocked or pinched

Check oil lines visually

Exchange oil line

Oil pump defective

Measure amount of oil flow of all channels without injection

Exchane oil pump

valve and with new lines

No amount of oil flow

Inflow stopped up, Oil filter

Check amount of flow (see Chapter 2.3. Pos.5)

Exchange filter

blocked

Oil pump defective

Measure amount of oil flow of all channels without injection

Exchange oil pump

valve

16.02.05

DOC_Anhang_B_E_0.01

Page 12 of 12

Oil injection tips

The oil injection pump pushes oil to the injectors but does not draw oil from the reservoir

tank. The pump is gravity feed so your choice for mounting the reservoir tank must be

high enough that the outlet on bottom of tank is at least 1” higher than the supply inlet

hose barb on the pump. In the case of a tractor prop installation the tank will be lower

during climb than in level flight so it may be necessary to mount the tank 2 or 3 inches

higher than the pump. Use ¼” hose with the supplied oil filter in between pump and tank.

Make sure the oil filter is installed with the oil flow arrow toward the pump.

This is a variable rate oil injection system meaning the RPM of the engine combined with

the position of the cable disk on the front of the pump will determine the ratio. The cable

disk must be connected to your throttle cable system so that as you increase throttle the

disk moves as well which increases the oil flow. On a tractor prop application this can

simply be a 3^rd cable run all the way to your quadrant. On pusher applications the

quadrant will be much farther away from the engine and the small spring on the pump

cable disk may not be strong enough to pull the cable back when you go to idle. This is

where a 3 way throttle cable splitter can come in handy. You can purchase a cable splitter

from Aircraft Spruce. The oil injection manual shows how to initially adjust the cable. On

2 cylinder engines after cable is installed bend the retaining tab over to keep it in place.

Once installed and reservoir tank filled you need to bleed the air out of the pump. There

is a small bleed screw on the side of the pump that you turn out a few turns to bleed the

air. Once the air is gone and oil begins to come out tighten the bleed screw. There is still

air in the injection lines that can not be bled out until engine is started and until it is there

will be no lubrication. For your first run you need to premix your first tank of fuel at 50:1

ratio. This will keep engine lubricated until the oil injection system is functioning. Pull

the black plastic protective sheath that is around the oil lines back at each injector far

enough that you can see the white oil line on each. After engine is started monitor the

line. When the air is gone and oil is all the way to the injector you will be able to see it in

the line. You can shove the sheath back into place. Once the oil is flowing make a mark

on the tank that reflects the oil level. Also record how much fuel is in the fuel tank. Start

the break in procedure. Before you refill fuel tank record how much fuel you used for

break in. Refill oil tank until you are back at your mark measuring exactly how much oil

is required to refill it. Now do the math to determine what ratio of oil you are getting. As

an example if you used 8 gallons total for the break in and 14.5 ounces of oil your ratio is

70:1. - 8X128 ounces in a gallon = 1024 ounces of fuel divided by 14.5 = 70:1 oil ratio.

70: to 1 is the correct ratio. If the ratio found on the survey is substantially less than 70:1

increase the amount the cable disk on the pump is actuated by adjusting the cable adjuster

on the oil pump to increase it. If you are using too much oil adjust the cable adjuster so

that the cable disk is opened less. Keep doing short surveys (1 gallon of fuel at 5000Rpm

per survey) making adjustments until the required ratio is achieved. When you are

confident engine is receiving sufficient oil from the oil injection system (70:1) to operate

safely you can stop premixing oil with the fuel and begin running straight gas.

Size of reservoir tank: You want to choose an oil reservoir tank that will not run empty

before the fuel tank does. If your oil ratio is 70:1 a 1 gallon oil reservoir tank would

provide enough oil for 70 gallons of fuel. A 3 quart tank would cover 52 gallons, a 2

quart tank is good for 35 gallons and a 1 quart tank would be good for 17.5 gallons of

fuel. If you had a 10 gallon fuel tank a 1 quart oil tank would be more than enough oil for

each tank full but would have to be refilled each time the fuel tank is refilled. With 2

quarts of oil you could run 3 full tanks of fuel before refilling the oil tank. There are

various reasons for oil injection failures but by far the largest percentage of failure is

forgetting to refill the oil tank. For this reason some users will choose the 1 quart tank

and just get into the habit of refilling it at the some time they add fuel. Also it takes up

less room. You want to use a translucent oil tank that allows you to see the oil level at a

glance to insure you always have enough before you leave.

Recommended oil ratios: Blue Max 2 cycle injection oil - 70:1

Off the shelf mineral based 2 cycle injection oils - 60:1

Synthetic 2 cycle oils: 45:1 for pure synthetic - 50:1 for synthetic/mineral blends

Note: Hirth does not recommend the use of any type or blend of synthetic oil.

Do not use Blue Max pre mix oil in an oil injected engine.

Engines with recoil starter: On 2 cylinder in line engines the oil pump is installed on the

recoil starter. Too avoid shipping damage to the pump we sometimes remove the pump

and the oil line clamp and store it alongside the engine in a small plastic bag. Also inside

the bag are the two 5mm pump mounting bolts. Simply line up the pump driving slot with

the pump shaft, push the pump into place and install the two 5mm bolts with blue

locktight on the threads. (25 inch pounds) Note that one of the 5mm bolts is longer than

the other so be sure to install them in the correct mounting foot on the pump. Install the

oil line clamp to the recoil starter case with the spacer between the clamp and the recoil

case. Use Blue loccktight on the threads and torque to 86 inch pounds.

Re positioning the recoil handle: If you decide you want the recoil handle to exit the

engine in a different direction it is possible to pull the 3 mounting bolts out and turn the

recoil. You will first have to remove the oil pump. When re installing the recoil it is

imperative that it is centered with the crankshaft. To center the recoil install all 3 screws

(with blue locktight) until they are just snug and you can still move the recoil slightly.

Snap the recoil handle out hard until it catches but do not pull the engine over. Hold the

tension on the handle with one hand and tighten the 3 recoil mounting bolts with the

other. Now pull the handle out about a foot and let go. If the handle recoils back easily

you have the starter centered and you can go ahead and torque the 3 mounting bolts to 86

inch pounds. If the handle has drag when you let go loosen the 3 bolts and repeat the

centering procedure until the recoil is centered. If you pulled the recoil off the engine

make sure the rubber insert that goes between the pump shaft and the crankshaft is still in

the coupling and that the coupling is lined up before you push the recoil in place. If you

let the rubber insert fall out the coupling will shear off in a short time and you will have a

total failure of the lubrication system. Now that the recoil is in a new position you will

find the pump mounting holes no longer line up. Remove the pump mount plate from the

front of the recoil, turn it until the pump mount holes are again in correct position then re

install the plate mounting bolts with blue locktight 925 inch pounds) and then re mount

the pump as per pump mounting instructions previously mentioned above.

Arrow = Flow Direction

On Filter

Fig.

Neoteric

No.

Designation

Hirth Ref. No

Notes

No.

Oil pump

045.9

5426

Shorter (port side) oil pump schs .Loctite

Cylinder screw

D912M5x16

243

Locking washer

053.8/5

Belleville washer under pump mount shcs

Cable adjuster holder

3211 A3

Aluminum bracket to attach cable

Cylinder screw (Timing Adj.

Longer (starboard side) oil pump

D912 M5X20

Hardware)

shcs.Loctite 243

Cylinder screw

D912 M6X12

2469

Holds cable adjuster in place.Loctite 243

Serrated Locking washer

053.8/6

6902

Belleville washer under DIN912M6X12

Isolating hose

D40621 B5X0,6/140

7128

Short single oil line cover (black)

Isolating hose

D40621 B8x0,7/330

7129

Long single oil line cover (black)

Hose

062.28/380

3425

Supply hose front 13” long

Hose Clamp (small)

5646

Clamp hose to tank & Filter

Hose

063.28/500

3425

Supply hose rear 16 ¼” long

Cable tie rap

026.40

2372

Zip tie, do not use

Cylinder Screw

Din 912 M6x25

Do not use

Washer

DIN 125 B6,4

6916

Do not use

Hexagon head screw

DIN 985 M6

5572

Do not use

Hexagon head screw

DIN 934 M6

Do not use

Washer

DIN 433 6,4

Do not use

Hose clamp (smaller)

5489

Clamp hose to pump & carbs

Oil Filter

5505

Inline oil filter Arrow = Flow Direction

Splash Cover

6246

Fiberglass part, Neoteric manufactures

Adjusting Screw

6105

Oil Injection Cable Adjuster Screw

Adjusting Screw Nut

6106

Nut to lock adjuster screw

3” Hose Clamp, SS

2734

Hose clamp for splash cover

Form: 17283rev4

Neoteric

Fig. No

Qty

Designation

Hirth Part No.

Notes

Part No.

Driving Dog with starter

275Y3U

6189

Dog Pulley

Cylinder Screw

DIN 6912M8X35

Dog Pulley hardware, SCHS

Md=23-28Nm

Tab washer

053.8/8

Belleville washer under

DIN6912M8X35

Recoil

275AF1U

5471

Pull Start

Cylinder screw

DIN 912 M6X35

6911

Pull Start Hardware SCHS

Md=9,6…11 Nm

Spring Ring

DIN7980 6

6940

Pull Start Hardware, Belleville

washer under DIN912M6X35

Cylinder screw

DIN 912 M6X50

2479

Pull Start Hardware SCHS (Only

applies to 5471 pull start long

screw)Md=9,6…11 Nm

Spacer pipe

264 H4

6935

Pull Start Hardware

Washer

DIN 125 B6,4

6916

Pipe clamp with rubber

063.24

6697

Small #8 clamp

Solenoid starter

195 A1

Cylinder screw

DIN 912 M8X30

2348

Starter SCHS bolt

Spring ring

DIN 127 B8

Belleville washer under

DIN912M8X30

Mounting Plate

3211 A4

Round plate on front 5471

Cylinder screw

DIN 912 M5X16

SCHS holds on round plate

3211A4

Serrated tab washer

053.8/5

Belleville washer under

DIN912M5X16

Deep groove ball bearing

DIN 625 6200 2RS/C3

6887

Located inside 5471

Shaft

3211 A5

Located inside 5471

Locking ring

DIN 472 30X1,2

Located inside 5471

Coupling right

3211 A8

Located inside 5471

Coupling element

040.4/2

Rubber coupling element. Loctite

243

Coupling left

3211 A7

Aluminum coupler engine side.

Loctite 243 -reverse threaded

Threaded pin

DIN 913 M6X20 LH

Reverse thread set screw that

attaches 3122A7 to the

crankshaft. Loctite 243-reverse

threaded

TABLE OF TORQUE VALUES 55 AND 65HP ENGINE

TORQUE

Fastener Description

Size

Ft. lb

inch/lb

AIR GUIDE ATTACHMENT SCREWS AND BOLTS

6mm

6 Ft.Lbs

72 inch Lbs.

CYLINDER HEAD SCREWS

6mm

8 Ft.Lbs

96 inch Lbs.

ELECTRONIC IGNITION BOX & IGN. COILS NUTS

6mm

7 Ft.Lbs

84 inch Lbs.

FAN HOUSING MOUNTING SCREWS

6mm

8 Ft.Lbs

96 inch Lbs.

FLYWHEEL DUST COVER (265C1)

6mm

6 Ft.Lbs

72 inch Lbs.

INTAKE MANIFOLD MOUNTING SCREWS

6mm

7 Ft.Lbs

84 inch Lbs.

RECOIL STARTER MOUNTING SCREWS

6mm

8 Ft.Lbs

96 inch Lbs.

CRANKCASE ASSEMBLY SCREWS 2703

8mm

19 ft.Lbs

228 inch Lbs.

CRANKCASE ASSEMBLY SCREWS 3203

4-6mm bolts

6mm

8 Ft.Lbs

96 inch Lbs.

FAN PULLEY MOUNTING SCREWS

8mm

19 ft.Lbs

228 inch Lbs.

ELECTRIC STARTER MOUNTING SCREWS

8mm

19 Ft.Lbs.

228 inch Lbs.

CYLINDER BASE NUTS

8mm

19 Ft.Lbs.

228 inch Lbs.

EXHAUST MANIFOLD MOUNTING SCREWS

8mm

19 ft.Lbs

228 inch Lbs.

RUBBER INTAKE FLANGE SCREWS (2702/03)

8mm

12 Ft.Lbs.

144 inch Lbs.

RUBBER INTAKE FLANGE SCREWS (3202/3203)

6mm

8 Ft.Lbs

96 inch Lbs.

COOLING FAN MOUNTING NUT

10mm

37 Ft.Lbs.

444 inch Lbs.

REDUCTION DRIVE MOUNTING SCREWS

10mm

37 Ft.Lbs.

444 inch Lbs.

SPARK PLUGS (cold engine) (2703/3203 single ignition)

14mm

14 Ft.Lbs.

168 inch Lbs.

CRANKSHAFT BOLT (PTO-end) (½ inch NF)

½” NF

55 Ft.Lbs.

660 inch Lbs.

CRANKSHAFT NUT (Magneto end)

16mm

107 Ft.Lbs

ENGINE MOUNTING BOLTS

½” NC

44 Ft.Lbs.

528 inch Lbs.

For items not listed, contact Neoteric

Criss cross torque patterns for

cylinder base

nuts and cylinder

heads. Repeat

torque pattern in 1 /3

increments until final torque spec is

reached.

Assy 17322

Form 16934

General Tools

Tools:

1. Inch pound torque wrench 0 to 250 in/lbs

2. Allen wrench set including 2.5, 4, 5, 6, and 8mm

3. Ball wrench set including 5 and 6mm at least

4. Open end wrenches 7, 8, 10, 13, 17, and 19mm

5. Regular and Phillips screwdrivers

3/8" drive hex bit set including 2.5, 4, 5. 6, and 8mm

5/8" or 13/16" spark plug sockets depending on spark plug size

8. Wrist pin puller (optional, only needed if removing pistons)

9. Ring Compressor for 72mm or 76mm diameter pistons

10. 3/8" drive ratchet

11. Piston Ring Remover (optional)

12. ¾" socket

13. 24mm socket

14. T25 and T20 torx bits (FI engines only)

15. Spark plug gap setter/checker

16. Soft faced hammer and ball peen hammer

17. Timing light (optional)

18. Exhaust spring remover and installer

19. 0-250 ft/lbs torque wrench (optional used only flywheel nut and G-50)

Materials

1. Loctite 242 or 243 blue

2. High temp anti-seize

3. Acetone

4. Hylomar gasket dressing (Permatex 25249)

5. Assembly lube (straight 2 cycle oil)

6. Aviation form-a-gasket (Permatex 3D)

7. Loctite 271 red

8. Loctite 518, 574 or equivalent (block sealant)

9. Mild acid (used to remove

Specialty Tools

Specialty tools (available at RPE):

1. Flywheel puller

2. Base nut torque wrench (preset to 19 ft/lbs)

3. Seal setters W137

4. Crankshaft PTO bearing spacer

17mm Allen wrench G-50 gearbox

6. Snap ring pliers

7. Dial indicator and holder for timing

40mm socket for prop shaft nut

Form 17326

Assembling Hirth Top End

Some tips on re-assembly that may be helpful

VERY IMPORTANT: When installing the piston on to the connecting rod, note the small arrow

imbedded in the top. THIS ARROW MUST POINT TO THE EXHAUST PORT! If you put the

piston on backwards, the piston and the cylinder will be ruined in about 10 hours of run time.

Piston rings must have small gap at the ends pointing up. A size cylinder must be used with A

size piston, B cylinder with B piston and C cylinder with C size piston. Make sure all mating

surfaces are clean. Con Rods are marked with a paint dot or etched with a letter (W, R, B) this

indicates which needle bearing to use.

Use Omni Visc Silicone to seal block halves and all joints. Use Permatex Gasket Dressing on

Gaskets.

IF IT IS A 2-CARB INLINE ENGINE: (Or F30 4 carb/Injected). After you have the cylinders

on, only snug the nuts tight enough that you can still move the cylinder a little. Now put the

exhaust manifold on without gaskets and snug the bolts. This will insure your cylinders are

parallel with each other and prevent exhaust leaks. Now, you can torque the cylinder base nuts to

1/3 of full torque. Use a crisscross torque pattern. After 1^st 1/3 torque pass remove exhaust

manifold. Now repeat the same criss-cross pattern to 2/3's torque, then a third pass at full torque

(19 ft. lbs.) Once the cylinder is fully torqued, you can install and torque the exhaust manifold

with the exhaust gaskets.

Use a criss-cross torque pattern on head bolts also in 1/3 increments. (96 inch pounds) It is very

important to use an accurate inch pound torque wrench on heads and spark plugs.

IF IT IS A SINGLE CARB ENGINE: (Or F30 2 carb) Procedure is the same as 2 carb except

you must use the intake manifold to align cylinders instead of the exhaust manifold. This is

important to prevent intake gasket leaks.

Use blue loctite 242 on both the 8mm base nuts and the 6mm intake manifold bolts. DO NOT

use loctite on the exhaust or head bolts. (It will boil inside the holes)

You may want to consider using Permatex - Hylomar HPF gasket dressing (Part#25249) on all

the brown paper type intake gaskets to be sure of your seal. Do not use gasket dressing on used

gaskets. (This is optional-gaskets can be installed dry as well) Never use a sealer designed for

metal surface sealing on paper gaskets as it cannot cure and will leak. Torque 8mm rubber carb

flange bolts to 120 inch pounds.

If piston and rings are new, engine will have to go through break-in again. Cylinder head bolts

should be re-torqued within 10 hours. It is important to check the torque of the cylinder base nuts

within 10 hours of putting engine back in service. (19 Ft. Lbs.)

*Use torque specs in the manual for all fasteners involved.*

Form 17322 Form 17273

Top End Disassembly

Tools needed:

•

5mm Allen wrench

•

3/8" drive 5mm Allen wrench

•

10mm socket (fan cooled engines only)

•

3/8" drive ratchet

•

13mm open end wrench

•

6mm Allen wrench

•

5mm Allen ball wrench

•

Circlip remover

•

Wrist pin puller

•

Spark plug socket 5/8" or 13/16"

•

Marker or something to keep parts together

•

Plastic or rubber faced hammer

Procedure:

Make sure ignition is turned off and battery is disconnected to reduce risk of injury.

Remove exhaust system including EGT probes.

Remove spark plugs.

Remove air guide from fan cooled engine or free air scoop from free air engine.

Remove carbs or fuel injection (you can simply let the carbs or FI hang on the cables and

hoses).

Remove intake manifold.

Remove all head bolts (you may want to mark your heads for reassembly later, example

pto, mag).

You may want to remove the fan tower or flywheel cover for easier access to the base

nuts on the cylinders.

With a 13mm open end wrench, remove all 4 base nuts from each cylinder needed to

work on (mark the cylinder for reinstallation later as mag or pto).

10. To remove the pistons, you will need to first remove at least one circlip from each piston

(I usually remove the pto end circlip from each piston), (throw the circlips away, they are

not to be used over) with either a wrist pin puller or a soft round piece of material, push

or pull the wrist pin out. BE CAREFUL TO SUPPORT THE PISTON WITH YOUR

HAND IF PUSHING THE PIN OUT SO YOU DO NOT BEND THE CONNECTING

ROD. (You will also need to mark the pistons for later reassembly). The needle bearing

on the wrist pin is caged so there is not need for concern about needle bearings falling

out, keep the needle bearing in the rod eye for safe keeping by using a tie wrap or piece

of wire.

Form 17329

Top End Reassembly

Tools needed:



- 13mm open end wrench



- 13mm base nut torque wrench (available at RPE)



- 3/8" drive 5mm Allen wrench (to fit your torque wrench)



- torque wrench 0 - 250 in/lbs.



- 6mm Allen wrench cut short for exhaust manifold



- 5mm Allen wrench cut short for intake manifold



- sparkplug socket 5/8" or 13/16"



- ring compressor

Materials needed:



- blue loctite 242 or 243



- acetone or paint thinner (cleaning mating surfaces)



- top end gasket set ALWAYS USE NEW GASKETS



- new circlips NEVER USE CIRCLIPS OVER (if pistons removed)



- high temp antiseize (optional for head, exhaust bolts, and sparkplugs)



- straight 2 cycle oil for assembly lube



- hylomar gasket dressing PN #25249 (optional to be used on paper gaskets only)



Omni Visc Silicon (used to seal block halves on the gaskets)



Permatex Gasket Dressing #85420 (use to dress all gaskets)

Procedure:

Make sure all parts are clean.

Clean mating base gasket surfaces with acetone or thinner and install base gaskets.

If run, put the same cylinder with same piston.

Lube all connecting rod bearings with straight 2 cycle oil. Con Rod has either paint dot or letter etched to dictate what color

bearing to use.

Put on piston with new circlips if removed THE ARROW ON TOP OF THE PISTON MUST POINT TOWARD EXHAUST

PORT (the electric starter side of the engine is the exhaust side or exhaust port side, when putting in circlips ALWAYS support the

back side of piston to reduce the risk of bending the connecting rod when pushing.

Lube piston and cylinder with straight 2 cycle oil.

Turn piston rings to line up opening with the pin in the piston.

Compress rings with ring compressor with one hand and with other hand put the cylinder over the piston. DO NOT FORCE IT, it

should slide on freely.

Remove ring compressor.

10.

Place cylinders down against base gaskets, and put on all four washers and cylinder base nuts using blue loctite, DO NOT tighten

completely, tighten the nuts enough that the cylinder can only shift slightly when grabbed a hold of. MAKE SURE THE ARROW

ON THE TOP OF THE PISTON STILL POINTS TOWARD THE EXHAUST PORT.

11.

Put on exhaust manifold WITHOUT gaskets and tighten down, this insures that the cylinders are mating the rigid exhaust Y

manifold perfectly so there are no leaks. NOTE: if you have a single carb engine use the intake manifold to do this process.

12.

Now you are ready to tighten down the base nuts using a criss cross torque pattern in 1/3 increments with the final torque being 19

ft/lbs. (Proper base nut criss cross torque pattern depicted on page 11).

13.

Once you have completely torqued down the cylinders, remove the exhaust manifold and put back on with gaskets, and torque

down.

14.

You are now ready to put on your intake manifold system using blue loctite on all the intake mounting bolts

15.

Put on the cylinder heads, make sure both mating surfaces are completely clean, start all the head bolts and tighten until you can

still move the head slightly from side to side, center the head in the movement and begin torque down in 1/3 increments in a criss

cross torque pattern with the final torque being 96 in/lbs., then do one final pass at 96 in/lbs, in a circle around the head to insure

complete torque down.

16.

Finish up by putting any accessories back on such as air guide, exhaust, carbs or fuel injection, sparkplugs, etc.

NOTES:

1. Since you have had the engine apart, you should consider going through a short break in to ensure everything is put back together

correctly.

2. If you have installed new the rings and / or pistons, it is recommended that you go through a complete break in to break in the

rings.

3. Also since you have had the engine disassembled you should go through a regular re-torque schedule as if the engine were new.

Pay special attention to the head bolts and base nuts.

Assy 17333 Form 17335

BOTTOM END DISASSEMBLY

Tools needed:

•

5mm Allen wrench (intake and fan tower)

•

6mm. Allen wrench (fan pulley, gearbox, exhaust and crankcase bolts)

•

13mm open end wrench (cylinder base nuts)

•

24mm socket (crankshaft nut)

•

8mm Allen wrench cut short (gearbox)

•

10mm wrench (air guide)

•

flywheel puller

•

4mm Allen wrench (stator plate)

•

star puller

•

soft faced hammer

•

¼" socket

•

wrist pin puller

•

circlip remover

Procedure:

1. Remove engine from machine (remove all attached parts that can be left on machine;

exhaust, carbs, FI system,

etc.

2. Remove gearbox completely (refer to

page 12).

3. Remove fan tower or flywheel cover.

4. Remove flywheel and stator plate (refer to page 6).

5. Remove air guide.

6. Remove intake system (5mm Allen wrench).

7. Remove exhaust manifold (6mm Allen wrench cut short)

8. Remove cylinder heads.

9. Remove cylinders (keep piston and cylinders matched together, and also make note of which cylinder went where,

pto/mag) (13mm open end wrench).

10. Remove pistons (wrist pin puller very

helpful in doing so) (leave wrist pin bearing in

rod eye and secure with tie

wrap), (remove circlip to do so).

11. Remove 7 - 8mm Allen head bolts that hold crankcase together (the crankcase is not free to be split apart).

12. Split crankcase: holding up on the top

of the crankcase, tap down on both the mag end

and the pto end of the

crank, the crankcase will begin to split (DO NOT PRY CRANKCASE APART).

13. Thread 2 of the 7 Allen head bolts back into case 3 or 4 threads and tap on the Allen bead, while holding up on top

half of crankcase.

14. Once the crankcase is split you can now remove the crank (put crank in a safe place free of dust and debris).

15. Remove small "alignment pins" from

block.

How to

remove piston from connecting rod;

1. Remove circlip or retaining ring from pto end side (as shown in picture)

2. Withdraw wrist pin from piston using a wrist pin puller or pushing out with a soft

material. MAKE SURE TO SUPPORT THE BACK SIDE OF THE PISTON

WHEN

PUSHING OUT PIN, TO REDUCE THE RISK

OF BENDING

CONNECTING ROD.

3. Secure needle bearing on rod with tie rap until reassembly. This is to insure

needle bearing goes back in same direction and on the same con rod. Pistons should

also be returned to same con rod and cylinders.

Form 17331

HOW TO REMOVE FLYWHEEL/STATOR PLATE

Tools needed to remove flywheel:

•

5mm Allen wrench (fan housing bolts)

•

6mm Allen wrench (fan pulley)

•

flywheel puller or harmonic balance puller

•

24mm socket (flywheel nut)

•

impact wrench if available (makes job much easier)

•

4mm Allen wrench (stator plate bolts)

Procedure:

1. Remove cover plate or recoil starter.

2. Remove fan pulley.

3. Remove flywheel nut and washer.

4. Remove fan tower or flywheel cover, the fan tower will have five 6mm bolts to remove, the flywheel cover on a

free air engine will have only four 6mm bolts to remove.

5. Carefully remove the fan tower or flywheel cover to the left, keeping in mind that the stator late wires are still

attached to the ignition on the piece set aside to the left.

6. Attach flywheel puller to the flywheel carefully screwing in the bolts. Be careful not to turn the bolts in too far,

there is a plastic plate beyond the threads of the hole, and can be damaged if the bolts are turned too far. Also

make sure that the bolts are all placed in evenly so that you will pull evenly on the flywheel.

7. Using either your impact wrench or ratchet tighten the puller bolt to press against the end of the crank (flat).

Continue to tighten until the flywheel pops off (it will take a large amount of pressure to remove the flywheel).

8. To remove stator, disconnect all ignition wire leads, (there will be 2 or 4 shrink wrapped connections to

disconnect), (these connections will he behind your coil assembly on a fan cooled engine). Also disconnect the 2

yellow wires connected to your regulator rectifier and or tach, remove two 5mm bolts and the stator plate will be

free to remove, (you may need to carefully pry the stator plate out).

CLEANING PARTS FOR REASSEMBLY

With engine tore down completely this is also a good time for a decarbon.

You must clean all parts thoroughly before re-assembly, this is also a good time to inspect parts for any damage. The

process of cleaning can be done a few different ways including: ultrasonic, chemically, and physically scraping. Make

sure when using chemicals that they are safe. to use on the material being cleaned (aluminum). Once your parts are

completely cleaned and dried you will be ready for reassembly.

SEIZURE ALUMINUM DEPOSITS

Slight aluminum deposits on the cylinder walls can be burned off with acid if needed. If there is scoring of the nikasil

after aluminum is burnt off the cylinder will have to be replaced. DO NOT HONE OR DEGLAZE A NIKASIL

CYLINDER EVER.

BOTTOM END REASSEMBLY

Materials needed:

•

- assembly lube (use straight 2 cycle oil)

•

- Loctite 518, 574 or equivalent

•

- Acetone for cleaning mating surfaces

•

- Loctite 242 or 243 blue for fasteners

Tools needed:

•

- 3/8" drive 6mm Allen wrench (must fit your torque wrench)

•

- W137 seal setter to set mag end seal properly

•

- Plastic or rubber faced hammer

•

- Torque wrench 0 - 250 in/lbs.

Form 17332

Procedure:

ALL PARTS MUST BE COMPLETELY CLEAN.

Lube all bearings on crankshaft with straight 2 cycle oil.

Place crank in bottom half crankcase, making sure the mag end of the crank is at the correct end of the

crankcase. Tap down slightly to ensure proper seating of bearings, also make sure that all of the

retaining rings are in their correct location and that the split in the retaining ring is up (refer to picture on

this page) and NOT in line with crankcase split. Place center seal spacer in center of crankshaft, bend

separator slightly to ensure a snug fit. Place 2 alignment pins in bottom half of crankcase (they will fit

loose, they are only to fill the void).

You are now ready to place sealant on the top half of the crankcase (only needed on mating surface) a

LIGHT coat of sealant is all that is needed. Use Omni Visc Silicon to seal block halves together.

Now you are ready to assemble the complete bottom end of the engine. Carefully hold the connecting

rods up with one hand and guide them thru the top half of the crankcase as you bring the halves together.

Tap down slightly to ensure proper mating.

Using blue Loctite 242 or 243 on the 7 - 8mm. crankcase bolts, (4 - 6mm and 3 - 8mm bolts on

3202/3203) start all bolts before tightening. Hand tighten using a criss cross torque pattern. With W137

seal setting tool set the mag end seal. Spin crank in crankcase by hand to make sure it is smooth and free

of drag. You are now ready to torque the crankcase bolts to their proper torque setting (228 in/lbs. on

8mm - 96 in/lbs. on 6mm) using once again the criss cross torque, pattern. Spin the crank once again to

ensure smooth operation, and no large increase in drag from the first time spun. If drag increases,

disassemble case and determine cause.

You are now ready to assemble the top end.

Con Rods are

marked with a paint

dot or etched with

a letter to indicate

which needle

bearing is to be

used.

Assy 17333 Form 17334

HOW TO CHANGE FAN OR TIGHTEN FAN BELT

Tools Needed:

•

5mm Allen wrench

•

regular screwdriver

•

7mm wrench (for 2704/06 only)

•

19mm wrench

•

6mm Allen wrench (fan pulley)

Changing Belt Procedure:

1. Remove cover plate or recoil starter

(5mm Allen wrench).

2. Remove fan pulley from flywheel (6mm Allen wrench).

3. Loosen lock nut on fan eccentric cam

shaft (19mm wrench and regular screwdriver).

4. Remove fan tower (you will need to

remove five 6mm bolts to do so using a 5mm Allen

wrench) be careful when doing so because your ign. Wires will still be attached (you

not have to remove these wires).

5. Remove fan air deflection plate (2704/06 only) (regular screwdriver and 7mm wrench).

6. Remove fan's eccentric cam shaft (be

careful there may be a spacer washer between

fan case and fan depending

on year of engine).

7. The fan is now free to be removed, replace belt, follow the procedure in reverse.

Notes:

• Do not tighten lock nut until end of procedure.

• Once the fan and belt arc in place, turn eccentric cam to the closest position toward the

fan pulley on flywheel. This will make it easier to install the pulley on flywheel

later and also keep you from over tensioning the belt or stretching the belt.

•

Use blue loctite 242 on fasteners.

• There is no reason to ever remove the plastic fan grill. Removing it will damage the

mounting clips.

Tightening fan belt:

Tools Needed:

- 19mm wrench

- regular screwdriver

- 5mm Allen wrench

Procedure:

1. Remove cover plate or recoil starter

2. With regular screwdriver in one hand and the 19mm wrench

in the other hand, break the nut loose (hold the center shaft

from turning with the screwdriver and break nut free with

wrench) (see illustration).

3. Turn the Screwdriver 10 or 15 degrees to tighten fan belt,

check tension (if the belt does not tension it may be time to

replace it).

4. Hold shaft from turning with screwdriver, tighten nut so that

you cannot turn the shaft when tightened.

5. Reassemble any removed parts.

Form 17328

TIMING

Timing is a term referring to the ignition firing or sparking at a specific time in the crankshaft's cycle of one revolution.

Timing is very important to the proper running of the engine: The engine comes factory timed and should never need

retimed, unless you have changed a flywheel or stator plate or if engine symptoms suggest timing problems.

Tools needed: (to check timing)

•

timing light (without advance preferably)

•

1" indicator and correct sparkplug hole insert to hold indicator

•

pointer (to point at flywheel) (should be stiff enough not to move)

•

5mm Allen wrench to remove cover plate or recoil starter

•

felt marker or paint marker to draw line on flywheel

Procedure:

Remove cover plate or recoil starter with 5mm Allen wrench, and also remove fan pulley with a 6mm Allen

wrench.

Remove one sparkplug from the pto cylinder and remove both sparkplugs from the mag end cylinder (this will

make it much easier to turn the engine over by hand to set up your timing mark)

Place pointer on engine using a bolt you removed to remove the cover plate or recoil starter, put it in a position

that you can easily see the pointer, point it toward the flywheel.

Next, place your dial indicator holder in the mag end sparkplug hole, and then place your 1" dial indicator in the

holder.

Make sure your ignition is turned off.

By hand, turn the flywheel clockwise. You will notice that your dial indicator needle will begin to move when

the piston makes contact. When the needle stops, this is what is known as top dead center, (you must be on the

compression stroke or up stroke of the engine). Hold the flywheel at this point, not allowing it to move either

way and very carefully place a dot on the flywheel at your pointers end. This dot is not your timing mark, it is

just for reference later in the procedure. Also at this time you will want to make note of where your dial

indicator needle stopped and set it for zero by turning the dial face. Go through the steps once again to make

sure you have marked and set your dial indicator correctly. Now it is time to put your timing mark on the

flywheel using the same procedure, your timing mark will come before your TDC mark on the flywheel, how

much before depends on the number of degrees your ignition timing is set for. You should always be on a

compression stroke or up stroke on the crankshaft when setting these marks due to bearing slap.

Now that you have your timing mark on the flywheel properly, you are ready to begin checking the timing.

First, remove your dial indicator from engine and the indicator holder. Second, put all your sparkplugs back in

the holes and torque to spec (engine must be cold to torque sparkplugs or you will risk damaging your heads).

Third, hook up your timing light to the mag end sparkplug wire correctly and whatever power source is

necessary to run your timing light (refer to your timing light owners manual). Next, make sure all your tools,

parts and people are clear of engine, you may want to remove your prop for this procedure for safety reasons, (if

you remove prop, make sure to set your idle setting down or the engine will rev to high), make sure aircraft is

secure so that it will not move if you do leave your prop on, Now you are ready to start the engine and hold at

1700 to 2000 rpm for proper timing, point your timing light toward your pointer and your pointer and timing

mark should line up. If they do not, line up adjustment will be necessary.

IGNITION TIMING SINGLE IGNITION

Degrees

521cc (64mm stroke

625cc (69mm stroke)

55 and 65 HP are 69mm stroke

.047”

.052”

All fuel injected timed -18°

.061”

.068”

55 HP carbureted - 14°

The above dimensions in inches are the dimensions you use to set the timing mark before top dead center an dial indicator Form 17337

ADJUSTING TIMING PVL

1. Remove cover plate or recoil starter and also fan pulley.

2. To adjust timing you must first loosen 2 small Allen head screws (Item 4) (2.5mm Allen

wrench) at either side of flywheel nut (loosen only slightly).

3. To advance the timing you must turn the screws clockwise, you may do this by slightly

pushing or tapping on loosened screw heads (be careful)..

4. To retard the timing you must turn the screws counter clockwise, you may do this by

slightly pushing, or tapping on the loosened screw heads (be careful).

5. Once the adjustment is made, tighten screws back down and check timing

again (no need

to reset mark or anything). Repeat until correct.

6. Once the timing is set correct check the screw tightness and reassemble any removed

parts (fan pulley, recoil starter, or cover plate, etc.)

Temporary timing pointer

installed.

Timing mark

(for degrees

before top dead center, this

mark will line

up with pointer,

when shooting with timing

light, when the timing is

adjusted correctly).

Top dead center mark (for

reference).

PVL timing adjustment

screws (turned

clockwise to

advance timing, turned

counter clockwise to retard

timing).

Dial indicator

installed in

sparkplug hole for timing

mark set up.

Form 17338

TABLE OF TORQUE VALUES 100 HP ENGINE

TORQUE

Fastener Descriptions

si·ze

IDCh lb.

CYLINDER HEAD SCREWS

8mm

228 inch Lbs.

OUTER MAGNETO RING

6mm

72inch Lbs.

INTAKE MANIFOLD MOUNTING SCREWS

6mm

84inch Lbs.

CRANKCASE ASSEMBLY SCREWS

6mm

84inch Lbs.

V BELT PULLEY MOUNTING SCREWS

6mm

84 inch Lbs.

ELECTRIC STARTER MOUNTING SCREWS

8mm

228 inch Lbs.

CYLINDER BASE NUTS

8mm

228 inch Lbs.

EXHAUST MANIFOLD MOUNTING SCREWS

8mm

228 inch Lbs.

RUBBER INTAKE FLANGE SCREWS

6mm

84 inch Lbs.

SPARK PLUGS

14mm

192 inch Lbs.

CRANKSHAFT BOLT (PTO-end)

(Yz inch NF)

Yz" NF

552 inch Lbs.

CRANKSHAFT NUT(Ma2neto end)

16mm

107 FT Lbs.

ENGINE MOUNTING BOLTS

lO mm

444 inch Lbs.

COOLANT MANIFOLD BOLTS

6 mm

84 inch Lbs.

100 HP ENGINE TECHNICAL DATA

Engine

lOOHp

I2n.Timin2@2000 - carbureted

18 de2.

I2n.Timin2t@2000 - Fuel injected

18 de2.

Spark Plu2 Heat VI.

280

Spark Plu2 Gap

.030

No. of Carburetors/lniectors

Three

Carburetor ID #

Dellorto - PHB34

Main Jet

165

Needle Jet

AB 265

Needle

K 43

Idle Jet

Do Not Exceed RPM

6300

Peak HP RPM

6000

HP @ Peak RPM

100

Peak Torque RPM

5500

Peak Torque Ft.Lb.

Maximum CHT

390

Maximum EGT (ti) full power

1256

Maximum EGT @ cruise power

1330

Maximum coolant temperature

240

Minimum coolant temperature

160

(Part #’s)

Headlight Switch (1652)

Navigation & Instrument Light Switch (1652)

Horn Button (2443)

Gasoline/Petrol Gauge (1628)

Hour Meter (6148)

Tachometer (5351)

Reverse Thrust Diagnostic Lights (5633)

Engine 2 Cylinder Head Temperature (5326)

Engine 2 Exhaust Gas Temperature (5327)

10.

Volt Meter (5817)

11.

12 Volt Supply Cigarette Plug (5688)

12.

Bilge Pump (1652)

13.

Ignition Switch (1884)

14.

Kill Switch (1052)

15.

Reverse Thrust On Off Switch (1652)

16.

Reverse Thrust Reset Switch (2431)

17.

Choke Lever (7348)

18.

Port Reverse Thrust Control Lever (7369)

19.

Starboard Reverse Thrust Control Lever (7369)

20.

Throttle Grip (6617)

21.

Throttle Cruise Control Lock Screw or Lever (7444)

22.

Electric Fuel Pump (1652)

Form 17481

23.

Lanyard Cord (1090)

Strobe Emergency Light (1652)

Headlights (1652)

Navigation & Instrument Light Switch (1652)

Horn/Siren Button (2443)

Gasoline/Petrol Gauge (1628)

Engine Cylinder Head Temperature or Water Temperature, depending on

gauge type (water temp gage 6166)

Tachometer and hour meter (5350)

Reverse Thrust Diagnostic Lights (5633)

Engine Exhaust Gas Temperature (5647)

10.

Volt Meter (5817)

11.

12 Volt Supply Cigarette Plug (5688)

12.

Bilge Pump (1652)

13.

Electric Fuel Pump (1652)

14.

Ignition Switch (1884)

15.

Kill Switch (1052)

16.

Reverse Thrust On Off Switch (1652)

17.

Reverse Thrust Reset Switch for Calibration (2431)

18.

Port Reverse Thrust Control Lever (7369)

19.

Starboard Reverse Thrust Control Lever (7369)

20.

Throttle Grip (6617)

21.

Throttle Cruise Control Lock Screw or Lever (7444)

Form 17482

Instructions for configuring the EGT & Water Temperature Gauge, Matt Rose, 25 July 2018

MGL Avionics instrument, TC1 Gauge

Note:

A. Top scale is chart scaling: do not use this

B. Set point is the alarm point when the red warning light flashes

C. Span in the rage of the bar graph it's the difference between highest and lowest temp

D. Alarm also goes off at set point

E. Span is set above the alarm set point

F. Knob can be used to do the same things as the Up and Down arrows F1 and F2

Procedure

1. Turn instrument on

2. Press center knob. Screen will read Exit Menu

3. Press the DOWN arrow F2 and screen will show DISPLAY SETUP

4. Press the DOWN arrow F2 and screen will show TC Setup

5. Press center knob

6. Adjust display contrast by turning knob to indicate approximately 2/3 thirds

7. Press center knob

8. Press DOWN arrow F2 to highlight BACKLIGHT

9. Press and turn center knob to select ON

10. Press center knob to select

11. Press DOWN arrow F2 to highlight Display

12. Press center knob to select Multi/Horizontal

13. Press center knob to select

14. Press UP arrow F1 and press center knob to select DONE

15. Press DOWN arrow F2 to highlight TC SETUP

16. Press center knob

17. Press DOWN arrow F2 to select TC CHANNELS

18. Set to 4 which is the number of thermocouples being used

19. Press center knob to select 4

20. Press DOWN arrow F2 to TEMP UNIT

21. Press center knob

22. Turn center knob to indicate degree F or degree C (Fahrenheit or Celsius)

23. Press center knob to select

Note: Channel configuration only applies to Multiple Horizontal bar display as selected in DISPLAY SETUP

This process is used for configuring CH1, CH2, CH3 and CH4 SETUPS

1. Press DOWN arrow F2 to select CH 1 SETUP

2. Press center knob to enter channel configuration menu

3. Press DOWN arrow F1 to highlight SPAN

4. Press center knob to change parameter

5. Turn center knob to select the value given in the configuration table shown at the end

6. Press center knob to select

7. Press DOWN arrow F1 to highlight TOPSCALE

8. Press center knob to change parameter

9. Press center knob and turn to select ON

10. Press center knob to select

11.

Press DOWN arrow F2 to highlight SETPOINT

12. Press center knob to change parameter

13.

Turn center knob to value indicated in the configuration table shown at the end

14.

Press center knob to select

15.

Press DOWN arrow F2 to highlight ALARM ON or OFF

16.

Press center knob to change parameter

17.

Turn center knob to value indicated in the configuration table shown at the end

18.

Press center knob to select

19.

Press DOWN arrow F2 to highlight PROBE

20.

Press center knob to change parameter

21.

Turn center knob to value indicated in the configuration table shown at the end

22.

Press center knob to select

23.

Press center knob to change parameter

24.

Press DOWN arrow F2to highlight LABEL

25.

Press center knob to select parameter

26.

Turn center knob to value indicated in the configuration table shown at the end

27.

Press center knob to select

28.

Press center knob to change parameter

29.

Press UP arrow F1 multiple times until DONE shows

30.

Press UP arrow F1 to DONE and press center knob, TC SET UP will show

31.

Press UP arrow F1 to DISPLAY SETUP and press center knob