Checking Metering Lever; Checking Inlet Needle Valve - Bosch PB-650 Service Manual

PB-650
PB-750
4-6 Replacing fuel line and grommet (continued)

4-7 Checking metering lever

2K423A

4-8 Checking inlet needle valve

(B)
(C)
2K005B
FUEL SYSTEM
(A)
4. Reinstall grommet to fuel tank together with pipe
joint and pipes.
NOTE: Pipe joint (D) (part number : V186-000080)
has not installed on the unit serial number 35003000
and before. When replacing fuel pipe (C) of the
above units, addition of pipe joint is recommended.
5. Reinstall all the parts that have been removed in
place.
1. Disconnect throttle cable from carburetor, then
pull off fuel pipe and fuel return pipe from carbure-
tor and remove carburetor.
2. Remove purge pump, air purge body, metering
diaphragm, and gasket.
3. Check the metering lever height using metering
lever gauge 897563-19830. If necessary, gently
bend the lever up or down to set the metering lever
at the correct position of 1.5 mm (0.06 in) as shown.
NOTE: When the metering lever is:
Too high → Fuel flooding
Too low → Fuel starvation/overheating
1. Remove the metering lever pin with the lever (A),
spring (B), and inlet needle valve (C).
2. Inspect the inlet needle valve if worn or stuck.
Clean or replace as required.
NOTE: Causes of the fuel flooding from carburetor
to the cylinder are as follows:
- Improper assembling of the metering lever and
spring.
- Dirt between the inlet needle valve and the seat.
- Worn inlet needle valve tip.
3.Clean the valve seat.
4. Assemble the metering lever, inlet needle valve,
pin, and spring.
NOTE: Make sure that the spring is seated in its
hole at the chamber floor under dimple of the
metering lever and that the metering lever is hold-
ing the inlet needle valve.
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