Repair Manual for Diesel engines series RY cod. 00497R0990

FOREWORD

This instruction manual includes all the technical information needed to

make any of the repairs required for the engines in question.

It is very important to strictly comply with all the instructions given to

ensure that the repair work is carried out as quickly and safely as

possible.

WORKSHOP REGULATIONS

- Always use the right tools for the repairs. Use of makeshift equipment

could damage the engine components

- Lightly tap solidly joined parts with a plastic or wooden mallet in order

to split the assemblies

- To facilitate the re-assembly operations, mark any parts without

reference points

- Separate the various components into distinct groups; retighten the

nuts and bolts of each assembly

- Wash each component with Diesel fuel or petroleum before

proceeding with the dimensional inspections

- During the assembly operations, thoroughly clean all parts, spread

lubricating oil on the mobile engine components and replace pins,

retention rings, seals, washers and self-locking nuts.

WARNING

Only use GENUINE RUGGERINI SPARES to ensure a good result.

service

D IESEL

SERIES RY DIESEL ENGINES

TECHNICAL SPECIFICATIONS

MODEL

Ry85.0

Ry85.1

Ry100

Ry101

Ry120

Ry121

Cycle

4-stroke Diesel

Injection

direct

Cooling

forced air with fan flywheel

Lubrication

forced with vane pump

Governor

centrifugal with weights

Number of cylinders

Swept volume

cc.

382

431

505

Bore

Stroke

Rpm

3000

3600

3000

3600

3000

3600

Compression ratio

19.5:1

18.5:1

PTO spinning

anti-clockwise

direction

Maximum torque

Nm(rpm)

19(2200)

22(2200)

27(2200)

Governor rpm error margin

Recommended battery

Ah(Amp)

60(300)

Max. intake vacuum

KPa

4.5

5.5

Max. exhaust back pressure

KPa

6.5

7.3

7.8

7.5

8.4

Quantity of air for combustion

m³/h

Dry weight

46.5

PTO side

45°(35°)

Maximum non-continua-

Pulley side

35°(30°)

tive slant

Right side

40°(30°)

(continuative)

Lato sinistro

45°(30°)

Casing oil capacity

1.3

Diesel fuel tank capacity

Max axial load on drive

300

shaft (non continuative)

5.0

D IESEL

2. POWER GRAPHS

Kg m

N m

Kg m

N m

CV-HP

2.3

Mt-N

1.9

2.2

1.8

2.1

1.7

g/CV-h

g/kW-h

g/CV-h

g/kW-h

205

280

205

280

C-N

260

C-N

260

185

240

g/min

1600

2000

2400

2800

3200

3600

rpm

g/min

rpm

1600

2000

2400

2800

3200

3600

RY85.0 - RY85.1

RY100 - RY101

Kg m

N m

CV-HP

2.8

2.7

Mt-N

2.6

2.5

2.4

g/CV-h

g/kW-h

270

195

C-N

250

175

230

g/min

1600

2000

2400

2800

3200

3600

rpm

RY120 - RY121

Power for automotive service (DIN 70020)

NB:

Non-overloadable power (DIN 6271)

NA:

Continuative overloadable power (DIN 6271)

U1:

Normal field of use, 3,000 rpm engine rate

U2:

Normal field of use, 3,600 rpm engine rate

Mt-N:

Torque rate corresponding to curve N

C-N:

Specific consumption with reference to curve N

With ambient temperatures exceeding 20°C (+68°F) or altitudes above sea level, the engine sustains a 2% power loss for every

5°C temperature increase and 1% for every 100 meters of increased altitude.

6.0

service

MAINTENANCE SCHEDULE

OPERATION

100

200

500

2500

Air filter oil level (for engines with wet air filters)

Engine block oil level

Battery fluid level

Rocker arm valve play

Injector calibration

Air filter

Cylinder and head fins

Fuel tank

Internal oil filter

Injectors

Air filter oil (for engines with wet oil filters) [*]

Engine block oil [*]

Air filter cartridge

Fuel filter

Dry air filter

General overhaul

[*] Use oil for Diesel engines according to MIL-L-2104D specifications with detergent

degree S.3 (MIL-L-45199B) type AGIP SUPERDIESEL MULTIGRADE 15W/40.

use SAE 5W/30 oil if the engine operates in places where the temperature is below

( ) First oil change.

The maintenance operations refer to engines that operate in normal environmental

conditions (temperature, degree of humidity, degree of dust in the environment) and can

sensibly vary, depending on the type of use (the air filter oil must be changed every 4-5 hours

in dusty places).

Overhauls include : grinding the valve housings and guides, overhauling the injector and

injection pump, inspection of the injector protrusion, cylinder and piston replacement,

replacement of the main bearings.

9.0

D IESEL

TROUBLESHOOTING TABLE

DEFECT

PROBABLE CAUSE

Air filter clogged

●

Con rod small end with excessive play

●

Engine running in

●

Unsuitable fuel

●

Air intaken by injection pump

●

Fuel filter clogged

●

Fuel tank empty

●

Worn main bearing

●

Clearance insufficient

●

Clearance excessive

●

Timing system gears defective

●

Head and cylinder fins clogged

●

Valve guides worn

●

Piston seized

●

Cylinder worn

●

Excessive rocker arm play

●

Regulator spring defective

●

Pipe clogged

●

Incorrect injection lead

●

Injection pump defective

●

Injection pump valve defective

●

Intake valve without play

●

Injector defective

●

Injector with clogged holes

●

Oil splash guard seals defective

●

Exhaust valve burnt out

●

Worn main or big-end bearing

●

Excessive load

●

Regulator lever with too much play

●

Tank plug hole blocked

●

Too much oil in casing

●

Hardened injection pump lever

●

Worn piston rings

●

Slack pump delivery union

●

Engine cold

●

Low idling rate

●

Change rate insufficient

●

10.0

service

ENGINE IDENTIFICATION

The type of engine and serial number are stamped on the

crankcase and on the data plate affixed to the conveyor (fig.

1).

Always indicate these engine identification numbers when

ordering spare parts or making requests under guarantee.

DEMOUNTING THE ENGINE

8.1 Removing the injector

Slacken off the fuel delivery pipe, remove the fixing bracket

and take out the tube.

Remove the injector by levering it out with a screwdriver, as

indicated in fig. 2.

8.2 Removing the injection pump

Mark the position of the injection pump in relation to the engine

casing (if this has not already been done).

Remove the injection tube and take out the fuel pipes.

The pump can only be removed when the stop lever has been

turned to the stop position. To do this, the pump must be

pressed towards the housing as shown in fig. 3.

8.3 Removing the flywheel

Remove the fuel tank, the air conveyor and flywheel nut.

Remove the flywheel using puller code 365.02 as indicated in

fig. 4.

WARNING: do not strike the puller in an axial direction during

this operation.

11.0

D IESEL

8.4 Removing the cover on the timing system side

Slacken off the screws around the perimeter of the cover on

the timing system side. Split the cover from the engine casing

by levering with a screwdriver in the points indicated in fig. 5.

Warning: to prevent damage to the main bearings, it is

advisable to demount the cover from the timing system side

with the engine cold.

8.5 Demounting the piston

Take out the piston pin as shown in fig. 6.

Warning: do not demount the head when hot or the retention

surfaces could be damaged.

8.6 Demounting and remounting the main bearings

Use tool code 365.90 and plug code 366.22 (fig. 7) to

demount the main bearings from the engine casing and cover

on the timing system side.

To fit the main bearing back into the engine casing, use tool

code 365.90 with plug code 366.22 and sleeve code 366.23

side A (fig. 8).

Main bearing

To mount the main bearing on the cover on the timing system

side, use tool code 365.90 with plug code 366.22 and sleeve

code 366.23 side B (fig. 8).

During the assembly operations, make sure that the bearing

holes match the oil ducts by making reference marks with a

366.22

felt-tip pen.

365.90

Make sure that the reference mark on the bearing edge points

towards:

- the casing interior

- the outer part of the timing system cover.

WARNING

Proceed with the following inspections after assembly:

365.90

Main bearing

Cover on timing system side

The main bearing must project 1.7 to 2 mm in relation to the

bearing surface of the bull ring (inner side of cover).

Engine casing

The main bearing must be flush with the bearing surface of

the shimming ring (inner side of casing).

366.22

366.23

12.0

service

INSPECTIONS AND OVERHAULS

9.1 Head

Parts indicated in fig. 9.

1. Nut - 2.Nut with ball - 3. Rocker arm - 4. Cotters - 5. Rocker arm

stud - 6. Upper cap - 7. Spring - 8. Air-relief valve - 9. Lower cap - 10.

Valve guide - 11. Rocker arm cover - 12. Head - 13. Valve housing

- 14. Exhaust valve - 15. Intake valve - 16. Rocker arm rod - 17.

Camshaft - 18. Tappets.

The head is made of aluminium with valve guides and housings

in faced cast iron.

Do not demount the head when hot to avoid deformations.

remove any carbon deposits from the head and check the

cylinder bearing surface. Level it off to a depth of no more than

0.3 mm if deformed.

The head must not be cracked or deformed. If such faults are

discovered, replace the part after consulting the spare parts

1 = intake

2 = exhaust

catalogue.

9.2 Valves - Guides - Housings

F 1

Clean the valves with a metal brush and replace them if the

tops are deformed, cracked or worn.

RY85.0 - RY85.1

øA

øB

øC1

øC2

øD1

øD2

øE(*)

øF1

øF2

13.025

36.630

33.630

36.5

33.5

6.96

6.945

0.8

D 1

13.01

13.037

36.645

33.645

36.525

33.525

7.01

6.97

6.955

C 1

C 2

RY100 - RY101 - RY120 - RY121

øA

øB

øC1

øC2

øD1

øD2

øE(*)

øF1

øF2

13.025

40.13

35.13

6.96

6.945

0.8

13.01

13.037

40.145

35.145

40.025

35.025

7.01

6.97

6.955

(*) with guide mounted.

measurements in mm

Check the dimensions of the valve stem (fig. 11) and the play

between the guide and valve. Ream the guide to the dimensions

indicated in the table. Change the guide and valve if the play

exceeds 0.1 mm.

The valve housings will always need to be ground when new

guides are mounted. Valve guides oversized on the outside by

0.10 mm are available.

After the engine has been used for a lengthy period of time,

valve knocking in their housings at high temperatures will

harden the housing tracks and make manual milling difficult to

carry out.

When this happens, remove the hardened surface layer with

a grinder at 45° (Fig. 12).

The valve retention track will widen when the valve housing is

machined. Final adaptation of the valve in the housing must be

carried out by smearing fine grain lapping compound in the

housing and turning the valve with a light pressure and with an

alternate movement until the surfaces bed perfectly (fig. 13).

Comply with the valve embedding values as indicated in the

table (G, fig. 10).

Warning: when the valve embedding values are lower than

those prescribed, the valves could interfere with the piston.

13.0

D IESEL

Grinding-in must always be carried out when new valves or

housings are mounted. Valve housings oversized on the

outside by 0.5 mm are available.

Thoroughly wash the valve and housing with petroleum or

gasoline to eliminate lapping paste residues or swarf.

Proceed in the following way to make sure that the valve and

seat are tight:

1) Mount the valve on the head with cap string and cotters

(see fig. 9)

2) Overturn the head and pour a few drops of diesel fuel or oil

on to the edge of the valve top

3) Blow compressed air into the head duct. Plug the edges of

the duct itself to prevent air escaping.

If there are air leaks in the form of bubbles between the

housing and valve, demount the valve and grind-in again.

14.91

±5%

24.72

9.3 Valve springs

K g

±5%

Check the length of the spring as indicated in fig. 14 to identify

K g

any yielding.

Replace the springs if the values are different.

9.4 Rocker arms

Make sure that there are no evident signs of wear on the

contacting surfaces. Replace the parts if necessary.

9.5 Cylinder

In special cast iron with integral liner. Use a bore gauge to

check the two internal diameters (C-D) perpendicular to each

other and at different heights (fig. 15). Maximum tolerated

taper error (A-B) and ovality error (C-D): 0.06 mm.

Cylinder diameter:

RY85.0 - RY85.1

Ø 80 to 80.020

RY100 - RY101

Ø 85 to 85.020

RY120 - RY121

Ø 87 to 87.020

Just replace the piston rings if the cylinder diameter does not

exceed the values above or if the cylinder is slightly scored on

the surface. In this case, to ensure that the piston rings and

cylinder adapt to each other as soon as possible, restore liner

roughness by passing 80 to 100 grain emery cloth soaked in

diesel fuel and wound around the palm of the hand over its

inner surface (fig. 16) until this appears cross-hatched. Follow

these operations by thorough washing in gasoline or petroleum.

Replace the cylinder and piston if there is a ridge in zone "X"

fig. 16 of the cylinder and if tapering and ovality exceed the

previously given values.

14.0

service

9.6 Piston rings - Piston - Pin

To gauge the wear on the piston rings, put them into the

cylinder from the bottom side and measure the distance

between the free ends (fig. 17), which must be:

Piston ring

Assembly mm

Wear limit mm

Compression

0.30 to 0.50

0.80

Oil scraper

0.25 to 0.50

0.80

Make sure that the piston rings slide smoothly in the slots and

use a thickness gauge to check the play between the slot and

ring (fig. 18). Replace the piston and rings if the play exceeds:

Piston ring

Limite di usura mm

1st Compression

A = 0.22

2nd Compression

B = 0.19

3rd Oil scraper

C = 0.16

WARNING: it is advisable to replace the piston rings whenever

the piston is demounted.

Checking the piston diameter:

the diameter of the piston must be measured at a distance

from the base (fig. 19) of approximately:

10 mm (for RY85.0 - RY85.1 - RY100 - RY101 series engines

11 mm (for RY120 - RY121) series engines

Engine

Diameter mm

RY85.0 - RY85.1

79.915 to 79.935

RY100 - RY101

84.915 to 84.935

RY120 - RY121

86.915 to 86.935

Check the play between cylinder and piston. Replace the

parts if play exceeds 0.150 mm.

Play between pin and piston mm:

Pin Ø mm

Play mm

Wear limit mm

21.997 to 22.002

0.003 to 0.013

0.040

9.7 Connecting rod

Coupling between the small end hole of the connecting rod

and pin is made without a bearing.

Play between connecting rod small end and pin mm:

Pin Ø mm

Play mm

Wear limit mm

21.997 to 22.002

0.023 to 0.038

0.070

- 0.02

Check connecting rod axes parallelism in the following

0.02₊

0.02

way:

1) Insert the pin into the small end hole of the connecting rod

and a calibrated plug into the big end (with the bearing

mounted).

100

m m

2) Rest the plug on two prisms arranged on a surface plate or

between two centers (fig. 20).

3) Use a centesimal comparator to check that the difference

between the readings made at the ends of the pin does not

exceed 0.02 mm. square up the connecting rod if the

deformation is greater (max. 0.05 mm).

15.0

D IESEL

The operation is carried out by applying a calibrated pressure

to the convex side in the middle of the connecting rod stem set

on surface plates (fig. 21).

9.8 Crankshaft

It is advisable to check the condition of the crankshaft whenever

the engine is demounted and particularly when cylinders and

pistons must be replaced following wear due to dust having

been intaken.

Thoroughly clean inside the oil ducts using a shaped metal

point.

If there are heavily caked incrustations, immerse the crankshaft

into a bath of petroleum or gasoline before proceeding with the

scraping operation (fig. 22).

When the crankshaft is perfectly clean, check with a micrometer

to ascertain wear and main journal ovality in the two

perpendicular positions (fig. 23).

R 3

Grind the shaft if the wear exceeds the values in the table by

0.5

0.08 mm or more.

Dimension

STD mm

-0,25 mm

A C

41.97 to 41.99

41.72 to 41.74

39.98 to 40

39.73 to 39.75

NOTE: crankshaft grinding operations of more than 0.25

mm should not be carried out.

Undersized bearings can be mounted without any reaming

work required.

WARNING: do not remove material from the main journal

shims during the grinding operation as this would alter

crankshaft float. Also make sure that the grinder radii

correspond to those indicated in fig. 22 to prevent fracture

sections from initiating on the shaft.

9.9 Oil retention rings

Make sure that the rings have not hardened in the retention lip

and that there is no sign of breakage or wear.

9.10 Lubrication circuit

Lubrication of the main bearings and connecting rod big end

is the forced type with a rotor oil pump.

Excessive pressure in the oil circuit is prevented by the by-

pass valve (3, fig. 24).

All the other parts are splash lubricated.

Oil vapours are eliminated from inside the casing by a

diaphragm mounted in the rocker arm cover.

Illustration in fig. 24:

1. Internal intake oil filter in casing - 2. Oil pump - 3. By-pass valve

- 4. Engine oil filter - 5. Pressure switch - 6. Main bearing - 7. Big end

bearing.

16.0

service

9.11 Checking the oil pump

Make sure that the oil pump cover is in a good condition.

After demounting, examine the rotors and replace them if their

lobes or centerings are damaged. To check the degree of

pump wear, measure the dimensions of rotor A and rotor B

(fig. 25) and compare them with the values in the following

table:

OIL PUMP ROTOR DIMENSIONS AND PLAY

Assembly mm

Limite usura mm

Ø25.97 to 25.99

Ø25,92

Rotor A

Rotor B

Ø34.96 to 34.99

Ø34,87

26.205 to 26.27

26,31

7.97 to 7.99

7.93

The entire pump must be replaced if the wear is greater.

The coupling play between the external oil pump rotor and the

housing on the cover of the timing system is:

Assembly mm

Limite di usura mm

0.16 to 0.215

0.345

Make sure that the oil pump recess in relation to the surface

of the timing system cover (fig. 26) is between :

Assembly mm

Wear limit mm

0.03 to 0.07

0.11

Make sure that there are no impurities in the by-pass valve on

the cover on the timing system side by unscrewing the

inspection plug near the fuel flow limiter.

9.12 Camshaft

Make sure that the cams and bearing pins are not scored or

worn. Check the dimensions as indicated in fig. 27.

Intake

I njection

Check the dimensions of the camshaft pins (D, fig. 28) and the

Exhaust

corresponding housings in the casing and cover on the timing

system side. The max. xonstructional play is 0.032 to 0.061

mm.

WARNING: replace the shaft if the wear on the cams or pins

exceeds:

0.1 mm (injection cams and pins)

0.3 mm (intake and exhaust cams)

NOTE: make sure that the valve lifting mechanism (fig. 28, A)

is not damaged and that there is nothing to hinder its movement.

17.0

D IESEL

9.13 Tapets and rocker arms

Make sure that there is no wear, scoring or signs of seizure on

the surfaces of the tappets (fig. 29). Replace the parts if

necessary.

Tapet and housing coupling play:

Assembly mm

Limite di usura mm

0.005 to 0.029

0.10

The rods must be straight with ball shaped surfaces at the

ends and in good conditions (fig. 29).

RY85.0 -RY85.1

RY120

- RY121

RY100

- RY101

9.14 Injection pump tappets and pads

Replace the parts if the wear on their surfaces exceeds 0.1

mm (fig. 30).

Coupling play between the tappet and relative housing in the

crankcase:

Assembly mm

Wear limit mm

0.021 to 0.059

0.10

9.15 Fuel pump (optional)

Check the projection of the A.C. pump rod in relation to the

engine casing surface with the canshaft eccentric in the non-

operative position.

Rod length

Wear limit

Rod projection

53.0 to 53.2

0.3

1.45 to 2.05

WARNING: the rod projection cannot be adjusted.

10. INJECTION COMPONENTS

10.1 Fuel circuit

Fuel supply is the gravitational type. An AC pump can be

mounted on request. Air bleeding is automatic.

Illustration in fig. 31:

1. Fuel tank - 2. Fuel pipe - 3. Fuel filter - 4. Fuel pipe - 5. Injection

pump - 6. Injection pump tappet - 7. Bleed tubes - 8. Injection

pipe - 9. Injector - 10. Washer - 11. Fuel return pipe.

10.2 Injection pump

Illustration in fig. 32:

1. Delivery union - 2. Filler - 3. Valve spring - 4. Delivery valve - 5.

Washers - 6. Monobloc pump casing - 7. Adjuster seal - 8. Flange

- 9. Pump seal - 10. Plunger - 11. Adjuster sleeve - 12. Plug - 13.

Adjuster block - 14. Spring - 15. Lower cap

18.0

service

10.3 Checking the injection pump

before demounting the injection pump, make sure that the

plunger unit, enbloc pump casing and valve are pressure tight

by proceeding in the following way:

1) Connect a pressure gauge with scale up to 600 Kg/cm² to

the fuel delivery pipe (fig. 33).

2) Set the regulating sleeve (fig. 34) to the average delivery

position.

3) Slowly turn the flywheel to make the plunger make one

compression stroke.

4) Read the indication on the pressure gauge. If it is lower

than 300 Kg/cm², the complete pump must be changed.

During the test, the pressure gauge needle will show a

progressive pressure increase until reaching a maximum

value, after which it will drop sharply back and stop at a lower

pressure value. Replace the valve if the pressure drop is more

that 50 Kg/cm² and continues to slowly drop lower.

The pressure must drop from 200 Kg/cm² to 150 Kg/cm² in

not less than 7 sec.

10.4 Injection pump calibration (fig.

35)

When the adjuster sleeve is 10.5 mm from the stop position

and the pump spins at 1,500 rpm, the amount of fuel for 1,000

deliveries must be between:

23 to 25 cc

Replace the pump if the values differ.

WARNING:

Check to make sure that plunger travel with the injection cams

in the non-operative position (BDC) at the start of delivery is:

1.9 to 2.0 mm

10.5 Injection pump assembly (fig. 37)

If the injection pump must be demounted, use an electric pen

to mark the adjuster block (M) with the enbloc pump casing (A)

and loosen the plug (N) after having heated it to make the

Loctite easier to release.

Comply with the following instructions when remounting the

parts:

1) Fit the washer (B), the delivery valve (C), the washer (D),

the valve spring (E), the filler (F) into the enbloc pump

casing (A) and torque the delivery union (G) to a value of:

4.3 to 5.4 Kgm (42.5 to 52.5 Nm)

2) Insert the adjuster seal (H).

3) Insert the flange (I).

4) Insert the plunger with helical profile (A, fig. 36) into the iner

housing of the adjuster sleeve from the side opposite the

sleeve pin (B, fig. 36).

19.0

D IESEL

5) Insert the adjuster sleeve unit and plunger (L) into the

pump casing (A), making sure that the helical profile is

directed on a level with the return union with ball.

6) Fit in the adjuster block (M), matching the reference marks

applied during the demounting phase.

7) Tighten the plug (N) to a 0.5 to 0.6 Nm torque, locking it in

place with Loctite 290.

8) Insert the spring (O) and lower cap (P).

9) Compress the tappets in the various operating positions to

check that the adjuster sleeve (L) slides perfectly.

Resistance or jamming will make the engine to hunt during

operation.

10.6 Leak test

Plug the fuel return union and let air in through the fuelling

union at a pressure of 6 Kg/cm². Fully immerse the pump in

a receptacle containing diesel fuel for about 50 - 60 seconds

(fig. 38) and make sure that no bubbles appear when the

6 Kg/cm

tappet is compressed 53.6 mm, corresponding to the bottom

dead center point during work.

NOTE: the position of the pump adjuster sleeve is of no

importance for this test.

air

10.7 Injector

Details of fig. 39:

1. Filter - 2. Fuel inlet union - 3. Fuel return union - 4. Nozzle holder

- 5. Calibration washer - 6. Spring - 7. Pressure rod - 8. Spacer - 9.

Nozzle - 9. Ring nut.

10.8 Injector inspection and calibration

1) Clean the nozzle holes with a thin steel wire (fig. 40) with

the following diameters:

Engine

Diameter of steel

Number of

Diameter of

series

wire (mm)

holes

holes (mm)

RY85.0

0.21

0.22

RY85.1

RY100

RY101

0.24

0.25

RY120

RY121

2) Mount the injector on the test bench (code 365.43, fig. 41).

Disconnect the pressure gauge and rapidly operate the

lever. The nozzle must make the characteristic "trilling"

sound and inject with a good atomizing action.

3) Connect the pressure gauge. Slowly depress the level in a

continuous way until injection occurs.

The injector needle must "open" at the pressure of 230 to

238 bar. Vary the washer shims (N° 5 fig. 39) to calibrate

in the correct way.

4) Leak test: operate the test bench lever until the gauge

pointer is 20 Kg/cm² below the injection pressure value.

Nozzle tightness is good if no fuel comes out within 10 sec.

5) Checking for leaks on the nozzle return phase: operate

the test bench lever until the gauge pointer is 20 Kg/cm²

20.0

service

below the injection pressure value. Release the lever and

check the time it takes to drop. The pressure must drop to 150

to 100 Kg/cm² withinn 6 to 40 seconds.

- replace the nozzle if it drops in less than 6 seconds.

- if it takes longer than 40 seconds to drop, make sure that

there are no carbon deposits in the nozzle and that the

return holes are not clogged.

10.9 Demounting and remounting

Loosen the ring nut that fixes the nozzle using a torque wrench

and as device like the one shown in fig. 42 which relieves the

pressure exercised by the spring on the ring nut.

1) Visual inspection: make sure that the needle housing is

not deformed or excessively rough.

The nozzle body must not show signs of wear or damage.

The holes must be free from carbon residues.

2) Smoothness test: the nozzle needle, which will have

been previously immersed in impurity-free fuel, should be

inserted into the body of the nozzle. Noz extract it by up to

a third of the guide length, holding the nozzle in a vertical

position. The needle must drop back into its housing

thanks to its actual weight alone.

Remount the injection in compliance with the order indicated

in fig. 39. Make sure that the plugs and centering pins on the

spacer (N° 8 fig. 39) match the relative holes in the housings.

Tighten the ring nut that fixes the nozzle to a value of:

Nx33

4.6 to 5.6 Kgm (45 to 55 Nm)

Mx1

Rx2.5

11. ELECTRICAL EQUIPMENT

Rx1

15/54

11.1 Characteristics of the system

30/1

Starter motor: lh rotation direction (pinion side), 12V voltage

Nx2.5

rating, power 1.1 kW.

Internal alternator: 12V - 280W

Mx1¹

Gx1

Mx1.5

Gx1

Voltage regulator: electronic, with controlled diodes and

L.E.

indicator connection for battery recharger

Recommended battery: 12V 60Ah (300A).

Rx2.5

Optional accessories: control strip with remote control switch

and OIL ALARM plant.

Illustration in fig. 43:

1. Ignition key - 2. Voltage regulator - 3. Starter motor - 4.

Battery - 5. Alternator - 6. Pressure switch - 7. Low battery

charge indicator - 8. Low oil pressure indicator.

CABLES: Colour x Section mm²

CABLE COLOURS: B= white

M= brown

N= black

R= red

V= green

21.0

D IESEL

11.2 Checking the system

1) make sure that the connections between the regulator and

alternator are correct and in good conditions

2) detach the wire from the remote control switch from the

terminal and fit on a d.c. amperometer (

,fig. 44)

3) coconnect a d.c. voltmeter to the battery terminals (

, fig.

44)

4) make a few no-load starts or introduce a 80−100W lamp

load at the battery lugs to keep the battery voltage below

13V.

5) accelerate the engine to a 3000 rpm rate. The current

indicated on the amperometer must correspond to the

1000

2000

3000

RPM

values in fig. 45.

6) disconnect the load (if any) and keep the engine at the

above mentioned rate for a few minutes. The battery

voltage must progressively increase until reaching about

14.2 V. Meanwhile, the charge voltage must drop to a

minimum value of about 2A, with a speed determined by

the battery charge condition.

7) if charge current is missing or is less than the given values,

check the alternator and replace the voltage regulator if

necessary.

11.3 Checking the alternator

With the engine at a standstill, disconnect the alternator wires

from the regulator and check:

1) using an ohmmeter, that the windings (fig. 46), null

resistance) and the insulation between wires and ground

(fig.47, infinite resistance) are unbroken. Replace the

stator if interruptions are discovered;

2) with a voltmeter, the voltage between the two yellow wires

(fig. 48). Accelerate the engine to 3000 rpm. The voltage

must be 33V.

If the values are more than 10V less than this, it means that

the rotor is demagnetized and that the alternator must be

replaced.

Warning:

1) the alternator does not deliver current when the yellow

cables are isolated

2) the alternator burns out if the yellow wires are grounded

3) the regulator may be damaged if the ground connection or

electrical connections are made in a slapdash way.

4) the alternator and regulator will immediately burn out if the

battery connections are inverted.

11.4 Ring gear

Make sure that the teeth of the crown wheel are not worn or

damaged. Heat the starting ring gear to a temperature of 200-

250 °C before fitting it on to the flywheel .

22.0

service

12. ENGINE ASSEMBLY

Important:

The instructions refer to engines updated at the time of

publication. Check the technical circulars for any

modifications.

Thoroughly clean the parts before remounting them.

Lubricate the moving parts to prevent seizures when the

engine is first started.

Replace the seals whenever the parts are remounted.

Use torque wrenches to tighten to the correct values.

12.1 Preparing the engine block

remove all traces of sealant or impurities from the bearing

surfaces with a copper plate or lapping stone, then proceed in

the following way:

1) Fit on the oil drain plugs without tightening them too much

(max. 2 Kgm) to prevent damage to the threads.

2) Mount the main bearing as indicated in section 8.6 on page

12.

3) Fit the benzing ring on to the pin of the regulator levers (fig.

49-A); apply Loctite 648 to the zone where the pin touches

the engine casing.

Insert the stop lever (fig. 49-B), the accelerator lever (fig.

50-C) and complete the assembly operations in compliance

with the sequencies indicated in figures 49 and 50.

4) Comply with the sequence indicated in fig. 51 for the

"motorstop" version.

12.2 Injection pump tappets

Insert the tappet into the injection pump housing in the engine

casing.

Fit the screw into the guide as shown in fig. 52

23.0

D IESEL

12.3 Timing system cover pre-assembly

Prepare the cover of the timing system in the following way:

1) Mount the main bearing as indicated in section 8.6 on page

12.

2) Fit in the pin and drive shaft bearing ring (fig 53).

3) Mount the oil pump rotors as described in section 9.11 on

page 17. Insert the plug and driving pin as shown in fig. 54-

A. Fix the oil pump cover in place by tightening the screws

to the following torque value:

0.8 to 1.0 Kgm

(7.8 to 9.8 Nm)

4) Insert the by-pass valve using tool code 366.21 (fig. 55);

mount the by-pass check screw with Loctite 648; mount

the by-pass valve inspection plug on the outside of the

cover on the timing system side.

5) Fit the retainer cap on the oil intake duct at the base of the

cover on the timing system side, using Loctite 648 (fig. 54-

B).

6) Tighten the internal oil filter (fig. 54-C).

7) Fit on the engine oil filter and relative plug including the O-

Ring (fig 54-D).

8) Mount the rpm governor, in compliance with the alphabetical

sequence given in fig. 56.

9) Fit in the fuel flow limiter

10) Mount the oil retention ring as indicated on page 27 fig.67.

24.0

service

12.4 Removal and assembly of the drive shaft gear

The gear on the timing system side can only be replaced.

To demount it, use puller code 365.10 (fig. 57) or a puller

available on the market.

To assemble, preheat the gear to a temperature of about 180

to 200 °C, fit it on the shaft, taking care to ensure that the

chamfer points towards the internal part, and use the tang as

a reference.

12.5 Drive shaft assembly (fig. 58)

Mount the drive shaft after having fixed the first shimming

washer to the casing with Loctite 648 and after having inserted

the needle bearing and the second shimming washer.

12.6 Connecting rod - drive shaft connection

After having fitted the bearings into the small end, connect the

connecting rod to the crank pin as shown in fig. 59.

Mount the connecting rod cap with the reference numbers

matching those on the rod.

WARNING: for series RY120 and RY121 engines, mount the

connecting rod half bearing with the positioning mark on the

cap and that without positioning mark in the center of the rod,

RY120

- RY121

in compliance with the dimensions indicated in fig. 59.

Evenly tighten the connecting rod bolts to the following value:

3.8 to 3.9 Kgm

(37.3 to 38.2 Nm)

A = 1.7 to

2.0 mm

12.7 Counter-shaft

Insert the counter-shaft, matching the reference marks on the

gears (fig. 60).

25.0

D IESEL

12.8 Camshaft

Insert the tappets into their housings on the casing. Mount the

camshaft, matching the reference marks on the gears (fig.61).

12.9 Play adjustment

Crankshaft float:

Place a calibrated bar on the casing, on a level with the timing

system cover retention surface and use a thickness gauge to

check the distance between the gear and bar (fig. 62). Note

down the value measured.

Place a calibrated bar on the cover of the timing system, on a

level with the engine casing retention surface and use a

thickness gauge to check the distance between the bearing

ring and bar (fig. 63). Note down the value measured.

The sum of the two measured values must be within:

0.10 to 0.30 mm

Camshaft float:

Place a calibrated bar on the casing, on a level with the timing

system retention cover and use a thickness gauge to check

the distance between the gear and bar (fig. 64). The value

must be between:

0.10 to 0.25 mm

26.0

service

Counter-shaft float (optional):

Place a calibrated bar on a level with the timing system cover

retention surface and use a thickness gauge to check the

distance between the stop surface and bar (fig. 65). The

measured value must be between:

0.10 to 0.25 mm

12.10 Cover on timing system side

Spread liquid seal of the AREXON D 0036 MOTORSIL type on

the retention surface of the timing system cover (fig.66).

Place the cover on the casing.

Insert the cover fixing screws, making sure that the five shorter

ones (40 mm) are mounted in the top part of the cover. Tighten

to the following torque value:

2.7 to 2.8 Kgm (26.5 to 27.5 Nm)

12.11 Oil retention rings

1) Immerse the retention ring in oil for about 10 minutes.

2) Clean the housing and insert the ring with a plug, exercising

an even pressure all over the surface (fig.67).

12.12 Flywheel

Block the flywheel (fig. 68) and torque the nut to value:

18 to 20 Kgm (176.5 to 1961 Nm)

27.0

D IESEL

12.13 Piston

Mount the rings on the piston (fig. 69) in the following order:

1) chromium plated compression retention ring (stamped

trademark pointing upwards)

2) tapering retention ring (stamped word TOP pointing

TOP

upwards)

3) oil scraper ring (stamped trademark pointing upwards)

Position the piston so that the central axis of the combustion

chamber is aligned with the injector (fig.70). Connect the

piston to the connecting rod, slightly pressing with the hand on

the pin.

12.14 Cylinder

Insert the cylinder into the engine casing after having inserted

the 0.3 mm thick seal.

before mounting, turn the rings through 120°, one in relation to

the other, with the first compression ring pointing with its ends

on a level with the pin axis.

There is a chamfer to allow ring insertion on the lower side of

the cylinder. The operation is simplified by using a normal ring

mounting tool code 365.77 as indicated in fig. 71.

Move the piston to TDC (top dead center) and check that the

mark stamped on the flywheel corresponds to the reference

pointer of the tool code 366.24 (see section 12.17).

To obtain the correct clearance, use a head seal of adequate

thickness:

1) check the piston projection as shown in fig. 72

2) Choose the seal as indicated in the following table

Piston projection (mm)

Seal thickness (mm)

0.00 to 0.10

0.8

0.10 to 0.20

0.9

0.20 to 0.30

1.0

0.30 to 0.40

1.1

NOTE: The distance between piston crown and the

corresponding head surface must be:

0.7 to 0.8 mm

12.15 Head

Before fixing the head to the cylinder, fit the injector into its

housing and, after having temporarily fixed it, check that the

distance the nozzle projects from the surface of the head by

(fig. 73):

2.2 to 2.7 mm

regulate by placing copper washers between the injector and

the bearing surface on the head.

Consult sections 9.1 and 9.2 for the relative inspections and

overhauls.

28.0

service

Insert the rocker arm casings, the partition (A, fig. 75), the

head seal and the head. Tighten the head fixing nuts evenly

and alternately (fig. 74) to the following value:

4 Kgm (39.2 Nm)

NOTE: To prevent oil leaks, apread sealant (Motorsil) on the

threads of the stud bolts and washer bearing surfaces in the

rocker arm chamber before tightening the nuts.

12.16 Valve play

Adjust the play between valves and rocker arms in either a hot

or cold condition, to the following values (fig. 75):

hot

0.15 mm (intake/exhaust)

cold

0.20 mm (intake/exhaust)

Since the automatic decompression device opens the exhaust

valve near TDC, play must be adjusted during the expansion

phase, a few degrees after TDC.

12.17 Injection lead

To ensure the injection lead is accurately adjusted, it is

advisable to define the shims to insert under the pump by

measuring the dimension between the pump bearing surface

and the tappet. Proceed in the following way:

1) turn the flywheel to the compression phase

2) insert the tappet pad into the housing in the engine block,

pointing the exhaust side towards the tappet roller (see fig.

30 page 18)

3) align the dynamic lead punch mark (IP) on the flywheel with

the reference mark of the tool code 366.24 (fig. 76)

4) using a depth gauge (fig. 77), measure the dimension

between the injection pump bearing surface and the tappet

pad.

5) subtract 51.6 mm from the dimension measured on the

gauge; the result represents the theoretic thickness of the

seals to insert under the injection pump.

NOTE: if the flywheel or a crank component is replaced, make

sure that the punch mark on the flywheel (TDC, fig. 76) and

the reference mark of the tool code 366.24, match when

the piston is at top dead center

Lead values in degrees and millimeters on the flywheel:

LEAD

TDC

24°±1° (56.6 mm)

The punch marks on the flywheel indicate (fig. 76):

TDC

= top dead center

= start of delivery

29.0

D IESEL

12.18 Mounting the injection pump on the engine

Lower the tappet in the innermost point of the engine by slightly

turning the flywheel.

Insert a seal of adequate thickness (see section 12.17 point 6).

Turn the motor stop lever to the STOP position.

Set the adjuster sleeve of the injection pump about one

millimeter from the stop position on the adjuster block (fig.

78).

Fit the injection pump into the engine block and, keeping it

pressed down, fix it in place by tightening the nut that holds

the relative bracket.

(Match the marks made during the demounting phase, see

section 8.2)

Warning: consult chapter 13.2 if the position of the injection

pump in relation to the casing was not marked during the

demounting operations or if a new one must be installed.

12.19 Injector and injector tube

Mount the injector on the head, inserting the copper retention

seals (see section 12.15).

Connect the injector to the pump with the injection pipe.

Warning: always use two wrenches to slacken off or tighten

injection pipes (fig. 79).

˜^{1 mm}

13. ENGINE TEST

13.1 Rpm regulation

Fill the engine with oil and diesel fuel and allow it to warm up

for 10 minutes.

With the engine hot, adjust the idling rate (A, fig. 80) to 1,300

rpm and the peak no-load rate (B, fig. 80) to:

- 3,150 rpm for engines set at 3,000 rpm on load

- 3,750 rpm for engines set at 3,600 rpm on load

13.2 Braked engine test

Carry out the following operations after having positioned the

engine on the brake:

1) Start the engine and allow it to idle

2) Allow the engine to run in before checking the maximum

power

Running in table:

Time (min)

Rpm

Load

2000

3000/3600

30%

3000/3600

50%

3000/3600

70%

3000/3600

100%

Consult the power curves in chapter 2.

30.0

service

There may be hunting problems, slowness or misfiring if the

HUNTING RATE

RATE

injection pump is changed. Correct these faults by turning

DIMINISHES

8° MAX

MORE SLOWLY

the pump casing a few degrees in relation to the engine

casing, following the directions indicated in fig. 81.

2.5 mm

Fuel limiter.

The fuel limiter has a torque corrector device (fig. 82) that

consists of the following parts:

A) Torque corrector cap

B) Maximum power flow rate adjuster

C) Spring load adjuster

STOP

D) Locking nuts

The adjustments can only be made to the exhaust brake. It is

therefore inadvisable to tamper with the corrector adjuster (C

fig. 82). The setting of adjuster B (fig. 82) can only be modified

if work has been done on the injection pump or regulator, if the

engine produces a lot of smoke or has insufficient power.

14. STORAGE

Engines that are to remain unused for a long period of time must be prepared in the following way:

14.1 Storage for up to 6 months

· allow the engine to idle at a low rate for about 15 min.

· change the fuel filter, pour a mixture of diesel fuel and 10% AGIP RUSTIA 81 protective oil into the tank

· turn the engine over for about 10 minutes at a speed of between 1/2 and 3/4 of its normal rate so that the pipes, injectors,

pumps and filters and filled with the protective mixture

· spray AGIP RUSTIA C SAE 30 into the exhaust and intake ducts and turn the starter pulley by hand

· thoroughly clean the fins, the radiator and the external parts of the engine. protect the unpainted external surfaces with

AGIP RUSTIA C SAE 30 oil

· seal the exhaust pipe and air filter with adhesive tape

· wrap the engine in a plastic sheet

14.2 Storage periods of more than 6 months

Besides the above operations, also:

· allow the engine to operate with AGIP RUSTIA C SAE 30 protective oil

· periodically inspect the engine and make sure that there are no traces of rust or corrosion

14.3 Setting at work

· remove the protective covers

· remove the external protective coating with solvent or degreaser

· check the injector settings, the valve play. Make sure that the heads and filters are well tightened

· proceed with the normal preliminary inspections prior to starting

· if the engine has been filled with AGIP RUSTIA C SAE 30 protective oil, replace this after at least 100 hours

service.

31.0

D IESEL

15. SUMMARIZING TABLES

15.1 Couplings

Play (mm)

Limit (mm)

Camshaft and plugs

0.032 - 0.061

0.1

Compression ring opening

0.30 - 0.50

0.8

Oil scraper ring opening

0.25 - 0.50

0.8

Connecting rod and piston pin

0.023 - 0.038

0.04

Injection pump tappets and housing

0.021 - 0.059

0.1

Tappets and housing

0.005 - 0.029

0.1

Pin and piston

0.003 - 0.013

0.04

Intake guide and valve

0.030 - 0.050

0.1

15.2 Adjustments

MIN (mm)

MAX (mm)

Camshaft float

0.1

0.25

Countershaft float

0.1

0.25

Crankshaft float

0.1

0.3

Connecting rod float

0.3

0.5

Connecting rod radial play

0.019

0.046

Regulator pin float

0.2

0.3

Valve play when hot [cold]

0.15 [0.20]

Valve recessing

0.8

Injector projection

2.2

2.7

Piston projection

0.1

0.4

32.0

service

15.3 Driving torques

Kgm

(Nm)

Timing system cover

2.7 - 2.8

26.5 - 27.5

Injector ring nut

4.6 - 5.6

45 - 55

Injection tube unions

2 - 2.5

19.6 - 24.5

Injector bracket

0.8 - 0.9

7.8 - 8.8

Injection pump bracket

19.6

Head

39.2

Flywheel

18 - 20

176.5 - 196.1

Connecting rod

3.8 - 3.9

37.3 - 38.2

15.4 Standard driving torques

Diameter x pitch

8.8 Steel with a high % of C

R10 Steel alloys

R12 Special alloys

Kgm

(Nm)

Kgm

(Nm)

Kgm

(Nm)

4 x 0.70

0.37

(3.6)

0.52

(5.1)

0.62

(6.1)

5 x 0.80

0.72

(7.1)

1.01

(9.9)

1.22

(12.0)

6 x 1.00

1.23

(12.1)

1.73

(17.0)

2.08

(20.4)

7 x 1.00

2.02

(19.8)

2.84

(27.8)

3.40

(33.3)

8 x 1.25

3.02

(29.6)

4.25

(41.7)

5.10

(50.0)

9 x 1.25

3.88

(38.0)

5.45

(53.4)

6.55

(64.2)

10 x 1.50

5.36

(52.6)

7.54

(73.9)

9.05

(88.7)

13 x 1.75

9.09

(89.1)

12.80

(125.5)

15.30

(150.0)

14 x 2.00

13.80

(135.3)

19.40

(190.2)

23.30

(228.5)

16 x 2.00

21.00

(205.9)

29.50

(289.3)

35.40

(347.1)

18 x 2.50

26.30

(257.9)

37.00

(362.8)

44.40

(435.4)

20 x 2.50

36.60

(358.9)

51.50

(505.0)

61.80

(606.0)

22 x 2.50

44.40

(435.4)

62.40

(611.9)

74.90

(734.5)

24 x 3.00

56.90

(558.0)

80.00

(784.5)

96.00

(941.4)

= 8.8

= R10 = 10.9

= R12 = 12.9

8.8

R10

R12

33.0

service

D IESEL

TABLE OF CONTENTS

1. TECHNICAL SPECIFICATIONS

5.0

11. ELECTRICAL EQUIPMENT

21.0

11.1

Characteristics of the system

21.0

2. POWER GRAPHS

6.0

11.2

Checking the system

22.0

11.3

Checking the alternator

22.0

3. OVERALL DIMENSIONS

7.0

11.4

Ring gear

22.0

4. SPECIAL TOOLS

8.0

12. ENGINE ASSEMBLY

23.0

12.1

Preparing the engine block

23.0

5. MAINTENANCE SCHEDULE

9.0

12.2

Injection pump tappets

23.0

12.3

Timing system cover pre-assembly

24.0

6. TROUBLESHOOTING TABLE

10.0

12.4

Removal and assembly of the drive

shaft gear

24.0

7. ENGINE IDENTIFICATION

11.0

12.5

Drive shaft assembly

25.0

12.6

Connecting rod - drive shaft connection 25.0

8. DEMOUNTING THE ENGINE

11.0

12.7

Countershaft

25.0

8.1

Removing the injector

11.0

12.8

Camshaft

25.0

8.2

Removing the injsction pump

11.0

12.9

Play adjustment

26.0

8.3

Removing the flywheel

11.0

12.10

Cover on timing system side

27.0

8.4

Removing cover on timing system side 12.0

12.11

Oil retention rings

27.0

8.5

Demounting the piston

12.0

12.12

Flywheel

27.0

8.6

Demounting and remounting the main

12.13

Piston

28.0

bearings

12.0

12.14

Cylinder

28.0

12.15

Head

28.0

9. INSPECTIONS AND OVERHAULS

13.0

12.16

Valve play

29.0

9.1

Head

13.0

12.17

Injection lead

29.0

9.2

Valves - Guides - Housings

13.0

12.18

Injection pump assembly

30.0

9.3

Valve springs

14.0

12.19

Injector and injector tube

30.0

9.4

Rocker arms

14.0

9.5

Cylinder

14.0

13. ENGINE TEST

30.0

9.6

Piston rings - Piston - Pin

15.0

13.1

Rpm regulation

30.0

9.7

Connecting rod

15.0

13.2

Braked engine test

30.0

9.8

Crankshaft

16.0

9.9

Oil retention rings

16.0

14. STORAGE

31.0

9.10

Lubrication circuit

16.0

14.1

Storage for up to 6 months

31.0

9.11

Checking the oil pump

17.0

14.2

Storage for more than 6 months

31.0

9.12

Camshaft

17.0

14.3

Setting at work

31.0

9.13

Tappets and rocker arms

18.0

9.14

Injection pump tappets and pads

18.0

15. SUMMARIZING TABLES

32.0

9.15

Fuel pump (optional)

18.0

15.1

Couplings

32.0

15.2

Adjustments

32.0

10. INJECTION COMPONENTS

18.0

15.3

Driving torques

33.0

10.1

Fuel circuit

18.0

15.4

Standard screw driving

33.0

10.2

Injection pump

18.0

10.3

Checking the injection pump

19.0

10.4

Injection pump calibration

19.0

10.5

Injection pump assembly

19.0

10.6

Leak test

20.0

10.7

Injector

20.0

10.8

Injector inspection and calibration

20.0

10.9

Injector demounting and remounting

21.0

Descrizioni e illustrazioni non impegnative.

34.0

service

SUGGESTIONS ON HOW TO TIME THE INJECTION PUMP WHEN THE LEAD PUNCH MARKS ON

THE FLYWHEEL ARE DIFFICULT TO REACH.

(Consult chapter 12.17 on page 29 for a description of the conventional adjustment)

T.D.C. = top dead center

P.M.S.

T.D.C.

h = extent of piston lowering in

relation to T.D.C.

I . P.

a = angle corresponding to piston

lowering in relation to T.D.C.

FIG.

I.P. = start of delivery

Proceed in the following way:

1) Remove the cover from the rocker arms.

2) Demount the recoil and turn the drive shaft to the valve regulation position.

(This operation is carried out by means of the fylwheel nut, using a N° 32 socket wrench).

3) Demount the intake or exhaust rocker arm, the valve spring and caps.

4) Rest the valve top on the crown of the T.D.C. balanced piston (fig.1).

WARNING: The valve slips from its guide if the piston is lowered by turning the drive shaft more than 1/4 of a pipe wrench

turn.

5) Position a comparator mounted on a magnetic pedestal or dummy injector and reset it on the valve stem (fig.1).

6) Slowly turn the drive shaft in an anti-clockwise direction and check the comparator to make sure that the piston drops about 5 mm

in relation to T.D.C. (dimension "h" - fig. 2).

7) Slowly turn the drive shaft in a clockwise direction and check the comparator to make sure that the piston rises by the values

indicated in the following table, in relation to T.D.C. (dimension "h" - fig. 2):

LEAD

4.12 mm

24°

8) Remove the injection tube and mount the capillary tube code 365.94 on the injection pump delivery fitting (fig. 3).

9) Turn the accelerator lever to the MAX position and the stop lever to about half travel.

10) Turn the drive shaft anti-clockwise by no more than 1/4 of the pipe wrench turn.

11) Pressurize the circuit by turning the drive shaft several times in an alternate clockwise/anti-clockwise way until fuel splashes out

of the calibrated hole of the capillary tube.

12) Turn the drive shaft and check the comparator to make sure that the piston drops about 10 mm in relation to T.D.C. (dimension

(quota "h" - fig. 2).

13) Shake the capillary tube until an air bubble forms inside it (fig. 3).

14) Turn the drive shaft in a clockwise direction very slowly and check the position of the air bubble in the capillary tube. A small

movement of this bubble will indicate the exact lead position. This value must correspond to the one previously read on the

comparator (see point 7). If this is not the case, add or remove seals to or from the injection pump according to the corrections

indicated in the following table:

Capillary tube

Comparative lead adjustment table

Bolla d'aria

365.94

Seal thickness for lead

correction

Value off tolerance

3.50

22°

- 0.2 mm

Value in MIN. tolerance

3.80

23°

- 0.1 mm

STD. LEAD

4.12

24°

Injection pump

Value in MAX. tolerance

4.50

25°

+ 0.1 mm

Value off tolerance

4.85

26°

+ 0.2 mm

FIG.