Periodic Adjustment; Maintenance Inspection; Engine Adjustment - Measuring Compression; Tappet Adjustment - Honda C50 Shop Manual

6. 7
PERIODICAL ADJUST
6.
DIC ADJUSTMENT
6.
NANCE INSPECTION
- e· die inspections should be performed at regular
s:::·ec le a nd designated mileages in order to obtain
scrisfoctory service as well as to extend the useful
life from y our motorcycle.
A. ENGINE ADJUSTMENT
l . MEASURING COMPRESSION
A
low compression pressure will result in a cor-
responding drop in the engine power output. Pressure
leak f rom any cause may effect the engine speed
adiustment at low speed and cause engine stal l.
a . Remove the spark plug.
b. Insert the end of the compression gauge into the
spark plug hole and hold fir mly to prevent pre-
ssure from leaking. (Fig. 6-1}
c. Operate the kick starter rep eatedly severa l times
with both the choke and throttle in the fu ll o pen
position.
(Caution}
CD
Make sure that the throttle and choke ar e
f ully opened, or else, a lower pressure indi-
cation will be registered on th e compression
gauge.
Compression gauge
Figure 6- 1. Measuring co mpression pressu re
®
The cylinder compression pressur e indication
k
Stanaarcr•q;,r.:r.
w ill gradua lly in crease w ith each kick, there-
fo re, continue kicking until the pressure
stabilizes at the highest point.
®
To obtain a true cylinder pressure indication .
the measurem ent should be made after th e
engine attains ope rating temperature.
@ Check for the proper operati on of t he va lves.
@
Make sure that the co mpression gauge is firmly
fi tted in the spark plug ho le.
d. The standard spe cified cylinder compr essio n pressure
is 12kg/cm
2
1172 lb/ in
2
).
(Fig . 6-2}
e. In case the compression pressure exceeds 14kg/ cm
2
1200 lb/in
2
),
it
is an indication of heavy carbon
deposit accumulation on the cylind er head or the
piston. The deposits shou ld be removed by disa -
ssemblying the cylin der head from th e cylinder.
f. When the compressio n pressure r egist er s less than
9kg/cm
2
1128 lb/ in
2
) ,
it is an indicatio n of pr essur e
leak. First, che ck th e tappet adiustment and see
ifj
~
the condition can be co rrect ed, disassemble th e
engine and in spect the condition o f the va lves, the
head gasket and piston rings.
2. TAPPET ADJUSTMENT
85