Chapter 8. Engine Maintenance; Ignition Timing - Yamaha SL292C 1971 Service Manual

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ENGINE MAINTENANCE -
Ignition liiming
CHAPTER 8. ENGINE MAINTENANCE
8-1 IGNITION TIMING
1 .
Ignition timing is most accurately set with a point
checker and a d ia I gauge.
It is r1ecessary to set the ignition timing at a specified
pos ition ±0.004'' (±0.1 mm) B.T.D.C.
If t l1e ignition timing is found to be ±0.014'' (±0.35
mm) off the specified position, it must be co rrected.
2. Th e fol lowing procedures for setting ignition timing
should be adhered to very close ly :
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a. Cl ean the points by letting them snap closed on a
strip o f business card that has been dipped in
lacq uer thinner . The card shou ld then be drawn
f
ram between t he po ints t o remove residue.
Repea t th is procedure unti
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the points are clean .
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Fig . 8 -1
b.
Remove the spark p lug and cylinder holding nut.
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Fig . 8 -2
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c. Install the dial indicator holder on the bolt .
Put the dial indicator into the indicator and lock
it
with the bolt.
Install the dial gauge on the dial indicator and
insert the adapter into the dial gauge, then adjust
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the ignition timing.
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Dial indicatc;>r.
Holder setting b olt
Dial indicator holder
Holder setting nut
Cylinder head
Fig. 8-3
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Fig. 8-4
d. Connect the red lead of the point checker to the
black lead coming from the magneto. For a good
po int checker reading, the main switch and the
secondary coil should be disconnected from the
magneto wire. Connect the black lead of the point
checker to ground (engine case, etc.).
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Fig. 8-5
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