BOMBARDIER 1982 Shop Manual page 310

SECTION 04 ELECTRICAL
SUB-SECTION 02 (IGNITION TIMING)
377, 503,
ENGINE TYPES
Two methods are detailed in this section, the first using
a Top dead center gauge, the second using a strobosco-
pic timing light.
Top dead center gauge verification
Remove the spark plugs.
On 503 models, remove the fan cover.
+
WARNING: Ensure the engine is cold before fan
cover removal on 503 models.
O
NOTE: The only way to remove the fan cover with-
out damage on a Blizzard 5500 MX and a Sonic is
to slide it against the muffler in a forward direction. Re-
verse procedure at installation.
Install a dial indicator in magneto side spark plug hole .
Bring magneto side piston to top dead center position.
Back -off (rotate counter-clockwise) piston to:
377 engine type: 2.31 mm (0.091 ") BTDC
503 engine type: 2.29 mm (0.090") BTDC
BTDC: Before top dead center.
3n
engine type: Lock through inspection hole and check
if the flywheel and magneto housing marks align . If the
marks do not corresponds to the specification, scribe a
new mark on the flywheel.
503 engine type: Look through the fan and check if the
flywheel and the crankcase marks align. If the marks do
not corresponds to the specification, scribe a new mark
on the flywheel.
PAGE310
Stroboscopic timing light
O NOTE: Timing can be checked using a strobosco-
pic timing light (Snap-On MT 212 or Electro Spe-
ciality, model 978), The ignition components are affected
by temperature variation, therefore, timing must be check-
ed when engine is cold after approximately 20 seconds
idling .
Connect timing light pick-up to magneto side spark plug
lead (on manual start models use a separate battery to
supply timing light).
+
WARNING: Place ski tips against a wall, raise rear
of the vehicle on a stand so that the track does not
contact the ground. Make sure no one passes behind
the vehicle while engine is running. Keep clear of track
and other moving parts.
O NOTE: Turn headlamp "ON" when checking the
timing.
Start engine and point timing
ligth straight in line with
the timing marks:
377: Look through inspection hole .
503: Look through the fan .
377 model:
... ......4--+-
Magneto housing
Flywheel mark
503 model:
Flywheel
mark
marks
J
Check timing mark alignment. If timing marks align, timing
is correct .
For both models (377
&
503 engine)
if
the timing marks
do not align, armature plate must be adjusted.
Armature plate will have to be moved to advance or re-
tard timing.