Ski-Doo Formula 500 1998, Shop Manual

Page: 224 / 398

Section 06 ELECTRICAL
Subsection 02 (IGNITION TIMING)
06-02-2
4. Locate the piston TDC position as follows:
a. Slowly rotate the magneto flywheel back and
forth across TDC while observing the needle.
Note that the needle stops moving only as
the piston is changing direction.
b. Rotate the dial face so that 0 (zero) is in line
with the needle when it stops moving.
c. Again, slowly rotate the magneto flywheel
back and forth across TDC and adjust the dial
face to 0 (zero), until the needle always stops
exactly at 0 (zero) before changing direction.
d. 0 (zero) now indicates exact TDC.
5. Verify the position of the timing mark on the
magneto flywheel as follows:
NOTE: When checking timing, certain procedures
require that the magneto flywheel be turned in a
clockwise direction, viewed facing the magneto/
generator. If it is necessary to turn back (counter-
clockwise) for any reason, rotate the magneto fly-
wheel at least 1/4 turn counterclockwise, and
then rotate it clockwise. The last magneto fly-
wheel movement when making a critical check
must always be in a clockwise direction, to ensure
that the slack in engine moving parts is taken-up.
a. Rotate the magneto flywheel 1/4 turn coun-
terclockwise, 1/4 turn then carefully rotate it
clockwise until the needle indicates the
specified measurement. Refer to TECHNI-
CAL DATA 10-02.
b. Verify that the magneto flywheel mark per-
fectly aligns with the mark on the trigger coil,
refer to illustration.
c. If the marks do not align, check magneto fly-
wheel and trigger coil part numbers and
check Woodruff key condition. If all parts are
the appropriate ones and if Woodruff key is
in good condition, continue the procedure.
1. Trigger coil mark
2. Magneto flywheel mark
NOTE: These marks cannot be used to check dy-
namic (with engine running) ignition timing with a
timing light: a new mark must be scribed on mag-
neto flywheel for this purpose.
6. Scribe a new mark on magneto flywheel as fol-
lows:
a. Remove the fan cover from the engine.
b. Maintain magneto flywheel so that previous
marks remain aligned.
c. Scribe or punch a mark on magneto flywheel
so that it aligns perfectly with the arrow on
crankcase, refer to illustration. This new tim-
ing mark should be used for future timing
checks (dynamic timing).
d. Reinstall rewind starter.
e. Check the timing with a timing light (P/N
529 0319 00).
A17E10A
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