Section 07 ELECTRICAL SYSTEM
Subsection 01 (IGNITION SYSTEM)
WARNING
Do not allow anyone in front of or behind the
vehicle while engine is running. Keep clear
of track and do not wear loose clothing which
can get caught in moving parts.
• Connect the timing light pick-up to a spark plug
cable.
NOTE: To avoid an incorrect reading due to paral-
lax, view the magneto flywheel and the crankcase
timing marks in a straight line.
• Connect tachometer wire to spark plug wire or
aim tachometer toward spark plug wire without
using any connection wire.
• Start the engine and raise the engine speed
at least to 3500 RPM (± 500 RPM) while ob-
serving the timing marks, refer to illustration.
The magneto flywheel mark scribed previous-
ly and the crankcase arrow should be perfect-
ly aligned. If the marks do not align, a faulty
trigger coil (check proper grounding of coil), a
faulty flywheel, a faulty Woodruff key, a mis-
aligned (twisted) crankshaft or a faulty CDI mod-
ule could be the cause: substitute one part at a
time and recheck timing marks (check connec-
tors condition prior to substituting any part).
NOTE: Ignition timing may be verified when en-
gine speed is anywhere within 3000 - 4000 RPM.
A30E1UA
TYPICAL
• Install parts which were removed.
Liquid-Cooled Engines
Normally ignition timing adjustment should not be
required. It has been set at factory and it should
remain correctly adjusted since every part is fixed
and not adjustable. The only time the ignition tim-
ing might have to be changed would be when re-
moving and reinstalling the magneto housing, re-
placing the crankshaft, the magneto flywheel, the
trigger coil or the MPEM or ECM. If the ignition
timing is found incorrect, first check for proper
crankshaft alignment. This might be the indication
of a twisted crankshaft. Refer to LEAK TEST AND
ENGINE DIMENSION MEASUREMENT.
The ignition timing can be checked with either the
engine hot or cold. Also, the ignition timing is to
be checked at 3500 RPM with a timing light ex-
cept on SDI engines. On these engine the igni-
tion timing must be checked at 4000 RPM.
NOTE: Except on the SDI models, between
3000 and 4000 RPM, the spark advance does
not change. So when checking ignition timing at
3500 RPM, a change in engine speed within ±
500 RPM will not affect the timing mark when
checked with the timing light.
Scribing a Timing Mark
NOTE: Before performing ignition timing on 793
HO Power TEK engines, disconnect the TPS.
• Clean the area around the MAG spark plug, and
remove it.
• Install the TDC gauge in the spark plug hole,
(magneto side) and adjust as follows:
– Position the MAG piston at approximately
TDC.
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