Husqvarna 131RB Workshop Manual page 43

10. Carefully remove the pump diaphragm and its
gasket. Examine the diaphragm for wear, where the
illustration show (A). Hold the pump diaphragm up to
the light to find holes in the material. Clean the fuel
screen (B). Replace the fuel screen if it is damaged.
Use a needle to remove the fuel screen.
B
A
A
11. Loosen the screw (A) and remove the lever, the
axle, the needle valve and the spring. Be careful to
prevent that the spring ejects.
A
12. Examine the lever arm and the needle valve for
wear.
a) Examine the connection points against the
control diaphragm for wear.
b) Examine the grooves for the needle valve for
wear.
c) Examine the top of the needle valve for wear.
d) Examine the groove for the lever arm for wear.
e) Replace damaged parts with new parts.
627 - 002 - 23.04.2018
13. Push out the seat of the needle valve for
replacement. Use a correct punch Ø 4.5 mm.
A
B
Note: Replace the seat, needle valve and lever arm
at the same time. The seat of the needle valve must
be pressed in level with the carburetor housing. Use
a vise with soft jaw guards to prevent damage to the
seat of the needle valve.
14. Assemble the parts in the opposite sequence as set
out for disassembling. Make sure that the lever arm
is flush with the diaphragm housing. If the lever arm
is set too high, too much fuel goes into the
carburetor. If the lever arm is set too low, a too small
quantity of fuel goes into the carburetor.
15. Replace the nozzle of the carburetor if it is
damaged. Use a small screwdriver to remove the
nozzle (A) and the small O-ring (B) from the
carburetor housing.
A
B
Repair instructions - 43