Yamaha SL292C 1971 Service Manual page 69

Trouble Shooting
Trouble
1. Overflow
2. Hard starting
3. Rough id ling
•
ENGINE MAINTENANCE -
Carburetion and Fuel System
Cause
o
Inlet valve is dirty.
o
In let contro l valve does not close perfectly.
o
Inl et cont rol
smoothly.
valve does not operate
Standard surf ace
Adjust the edge of
the lever to
0.0012''
(0.3
mm) higher
position from the
.__ / standard surface.
too high A
push up (bend)
proper
B
0.0012'' ±o.0004
(0.3 mm ±o.1)
Standard surface
too low C
push down
Fig. 8-23
o
Main diaphragm is not correctly installed.
o
Regulator internal pressure is too high.
o
Fuel passage is clogged.
o
Fuel pump is inoperative.
o
Choke does not open perfectly.
o
Fuel supply is insufficient.
o
Fuel supply is in excess .
o
Adjustment is incorrect.
o
Inlet control lever end is incorrect in
height.
o
Fuel pump operation is not smooth.
o
Both carburetors do not synchronize.
-63-
•
Remedy
Remove inlet valve and clean it.
Replace inlet control valve. (When replacing
it, make sure the seat surface is free of
scratches.)
1. Replace inlet control lever.
2.
Reinstall inlet control lever correctly.
(Adjust the end of lever to the position as
shown in Fig. 8-23.)
•
Reinstall main diaphragm correctly.
Reduce the pressure.
•
'
Clean fuel passage with gasoline, and blow it
out carefully with air.
Check impulse port. fuel pump diaphragm,
and check valves (inner and outer). ·
Reassemble it correctly. Check the linkage
between both carburetors.
Use primer pump. Refer to Starting Proce-
dures on the following page.
Refer to C of Starting Procedure.
Readjust as specified. Particularly, check
regulator fuel level and readjust as required.
Readjust. (Refer to ''Overflow''.)
Refer to ''Hard Starting''.
Check synchronization.
•
•
•
I
I
•
•
I
•
I
I
'
t
•
.
•