Inspecting Inlet Needle Valve; Inspecting Diaphragm - Yamabiko ECHO PB-2520 Service Manual

PB-2520
EB252

6-10 Inspecting inlet needle valve

B
C

6-11 Inspecting diaphragm

FUEL SYSTEM
A
C
D
B
A
E
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 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 oor.
(2) Spring is under dimple of metering lever.
(3) metering lever fork is holding inlet needle valve.
1. Check metering diaphragm (A) for hardening,
distortion or pin hole. Replace it as required.
2. Remove pump body assembly (B) and pump
diaphragm (C).
3. Check pump diaphragm and replace it if hard-
ened or curled at the valve tabs.
4. Check metering and pump gaskets and replace
if defective.
5. Check inlet screen (D) if blocked with dust. Re-
move and clean it or replace it if defective.
6. Check purge bulb (E) for crack, or fatigue. Re-
place it as required.
41