FUEL SYSTEM
CS-501SX, CS-501SXH
501sx
33
4-11 Inspecting inlet needle valve
1. Remove metering lever (A) and pivot pin. Re-
move spring (B) and inlet needle valve (C).
2. Inspect inlet needle valve if worn or sticky. Clean
or replace as required.
NOTE:
Causes of fuel fl ooding from carburetor to
cylinder are as follows:
- Improper assembling of metering lever and
spring.
- Dirt between inlet needle valve and valve seat.
- Worn inlet needle valve tip.
3. Clean inlet needle valve seat using suitable
clean solvent (do not use metal tools).
4. Reassemble inlet needle valve, spring, metering
lever and pivot pin.
NOTE:
Insure proper metering lever installation as
follows.
(1) Spring is seated in its hole at chamber fl oor.
(2) Spring is under dimple of metering lever.
(3) metering lever fork is holding inlet needle valve.
A
B
C
4-12 Inspecting diaphragm
1. Inspect metering diaphragm (A) for hardening,
distortion, or pin hole. Replace as required.
2. Remove pump cover (B), pump diaphragm (C)
and pump gasket (D).
3. Inspect pump diaphragm (C) and replace if
hardened or curled at valve tabs.
4. Inspect metering gasket (E) and pump gasket (D)
and replace if defective.
5. Inspect inlet screen (F) if blocked, remove and
clean it, or replace.
6. Clean fuel passages in carburetor body with
compressed air.
NOTE:
Before cleaning metering side with com-
pressed air, turn “H” needle clockwise until lightly
seated and remove inlet needle valve. Otherwise,
main nozzle check valve and inlet needle valve
spring may be damaged by the compressed air.
NOTE:
When cleaning pump side with compressed
air, take care not to blow inlet screen (F) away.
F
B
D
C
E
A
