BOMBARDIER 1982 Shop Manual page 307

c
• Loosen adaptor lock nut then holding gauge with
dial face toward magneto, screw adaptor in mag.
side spark plug hole.
• Slide gauge far enough into adaptor to obtain a
reading then finger tighten adaptor lock nut.
• Rotate magneto until mag. side piston is at top
dead center .
• Unlock outer ring of dial and turn it until "0" on
dial aligns with pointer .
• Lock outer ring in position.
6. Slacken the two (2) armature plate retaining screws
and turn timing instrument ON.
• Rotate magneto counter-clockwise until specified
piston position before top dead center is reached:
INDIRECT TIMING: 3.9 - 4.4 mm BTDC
(0 .153" - 0.173")
BTDC: Before top dead center.
Slowly rotate armature plate until timing light fluctu-
ates. (For 640 engine type, hold advance mechanism
centrifugal lever in full advance position). Retighten
retaining screws.
O NaTE: Ignition timing can change upon tightening.
Always recheck after tightening.
7. Disconnect timing instrument wire from blue wire then
reconnect it to the blue/red wire leading from engine .
Remove T .D.C. gauge from mag. side and reinstall it
on P.T.O. side, as previously detailed.
8. Rotate crankshaft until P.T.O . piston approaches
T. D. C. As soon as same specified piston position be-
fore top dead center as on mag . side is reached the
timing light should fluctuate (for 640 engine type,
hold advance mechanism in full advance position).
If necessary to adjust, proceed as follows.
With piston at specified position, slacken lower breaker
point retaining screw then readjust breaker points gap
until fluctuates.
• If timing is too early decrease breaker points gap
toward lower limit, i.e. 0.35 mm (0 .016") , then re-
check timing .
SECTION 04 ELECTRICAL
SUB-SECTION 02 (IGNITION TIMING)
• If timing is too late increase breaker points gap to-
ward upper limit, i.e . 0.40 mm 1.016"), then re-
check timing .
O NOTE: Breaker points gap can change upon tight-
ening. Always recheck after tightening.
Edge gap verification
By following either of the two procedures herein the
edge gap will automatically be adjusted. However, if the
edge gap is to be verified, proceed as follows:
From timing marks, rotate magneto clockwise
1/ 4
of a
turn, then slowly turn magneto back counterclockwise
until timing light fluctuates (flash light) (for 640 engine
type, hold advance mechanism in full advance posi-
tion).
At this point check the distance between generator coil
end and magnet (edge gap), with a strip cardboard of
appropriate width . (Refer to the following table).
ENGINE TYPE EDGE GAP
640 7 - 10 mm
(0 .275 - 0.394")
Edge gap
y
~
Strip of cardboard
Magnet
-+M..,
If edge gap is more or less than specified, the problem
lies with engine internal components (crankshaft out of
alignment, broken Woodruff key, loose breaker cam,
etc .). Corrective measures should be applied.
PAGE 307