Checking Inlet Needle Valve; Checking Diaphragm And Others - Echo PB-251 Service Manual

PB-251

5-9 Checking inlet needle valve

(B)
(C)

5-10 Checking diaphragm and others

(C)
(B)
(E)
FUEL SYSTEM
(A)
(D)
(A)
1. Remove metering lever (A) and its pin. Remove
spring (B) and inlet needle valve (C).
2. Inspect inlet needle valve if worn or sticky. Clean
or replace as required.
NOTE: Causes of the fuel flooding 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.
4. Reassemble inlet needle valve, spring, metering
lever and pin.
NOTE: Make sure that spring is seated in its hole at
the chamber floor under dimple of metering lever,
and that metering lever is holding inlet needle valve.
1. Check metering diaphragm (A) for hardening, dis-
tortion or pin hole. Replace it as required.
2. Remove pump body assembly (B) and pump dia-
phragm (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.
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