Service manual

4-15
FUEL
Fuel system
TIP:
Before disassembling the carburetor, make
sure to note the number of times the speed
screw is turned in from its set position to the
seated position.
Fuel pump check
1. Check the fuel pump gasket, diaphragm,
fuel pump diaphragm, fuel pump dia-
phragm body, and valve seat. Replace if
damaged.
Fuel filter check
1. Clean the fuel filter, and then check the
fuel filter. Replace if damaged.
High and low speed screw
adjustment
1. Tighten the high speed screw 1 and low
speed screw 2 until they are lightly
seated, then out the specified number of
turns.
Throttle valve synchronization check
and adjustment
1. While turning the throttle cable pulley,
check that the opening angle of both
throttle valves is the same.
2. Turn out the idle adjusting screw 1 until
its tips are no longer touching the throttle
cable pulley 2.
TIP:
Record the set position of the idle adjusting
screw.
3. Check that the throttle valve of the Car-
buretor 1 (rear) 3 is fully closed.
4. Turn the synchronization screw 4 in or
out until the throttle valve of the Carbure-
tor 2 (front) 5 is fully closed.
5. Turn in the idle adjusting screws to the
set position.
Choke valve synchronization check
and adjustment
1. While turning the choke lever, check that
the opening angle of both choke valves is
the same.
2. Turn the synchronization screw 1 in or
out until both choke valves are fully
closed when the choke lever is turned to
the closed position.
High speed screw:
1 1/8 ± 1/4 turn out [carburetor 1 (rear)
3]
5/8 ± 1/4 turn out [carburetor 2 (front)
4]
Low speed screw:
5/8 ± 1/4 turn out