Service manual

• Compression release (Release wire is optional parts)
Assemblp thp parts as shown in Fig. 19. Pull the lever out as
far as it will go. check to see that the 60° angle is attained
and that compression is released. The compression release
is to be used when the battery is low or when starting in
cold weather. Tn use the compression release. preheat the
glow pluq :ls IJsual. pull the compression release knob out as
far as pOSSible and holrl it there while cranking the engine
This
flartially' releases the enQine comflression enabling it to
turn faster in cold weather or when the battery is low. Once
the
engi ne IS turninq fast enough to start. release the lever and
the engine will start.
(NOTE)
Make sure the compression release has returned to the
operating position by pushing the knob all the way in.
1 elf;D
Released
Operating released
Fig.
19. Compression Released
~ CAUTION n
Do not pull the compression release lever when the engine is
running at high speed or under load. If it is necessary to use
the compression release while the engine is running reduce the
speed to idle before doing so.
• Adjustment of compression release
(1) Set exhaust valve in totally closed position
(2) Remove decompression adjustment window cover from
cy I i nrler head cover.
(3) Make
valve clearance as "0" with use of decompression
adjust
bolt From this position. turn the holt further by
1 to 1.5 turns. Decompression clearance will then be set
at 0.030 to 0.044 in. (075 to 1.125rnrn), which is the
designed
clearance.
(4) After adjusting, be sure to lock adjust bolt securely so
that it will not unturn while engine is in service.
(5) Make certain that the cleanrance is not too wide. To
check this. turn crankshaft hy hand and make certain
valve disk does not contact With pistion top
(9)
Compression released
position
Operation position
II/cr; C%l
~
~~ ®
\ \
". '
/ .~
1. Rocker arm
5.
Compression release nut
2.
Oil filler cap
6.
Compression release bolt
3.
Compression re~ase lever
7.
Shaft
4.
Adjustment access cover
8. Valve
Fig.
20. Adjustment of Compression Released
• Top clearance
Top clearance should be 0.028 to 0.035 in. (0.7 to 0.9 mrn)
To adjust, usecyl inder gasket shims, 0.006 in. (0.15 mm) thick
each, onto the head side
For checking the measurr.rnent, place a piece of fuse on the
piston top and fix the cylinder head securely on the cylinder·
head flanqe The measurement is taken by the fuse. The liner is
level with the cylinder frarne at top surface.
The gasket shirns can be reused, so do not lose them.
Head
- Top clearance
--.-....,-- 0.028-0.035in.
(0.7-0.9mmJ
Piston
Fig. 21. Top Clearance