Yamaha F50D, Руководство по обслуживанию

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Fuel system
6-15
FUEL
Removing the carburetor
1. Removing the carburetors from the
power unit. See “Intake silencer” (6-11).
Disassembling the carburetor
1. Disassemble the carburetor. See
exploded diagram (6-13).
Checking the carburetor
1. Check the air, fuel passages and jets.
Clean the carburetor body, if there is dirt
or foreign material.
2. Blow compressed air into all passages
and jets.
WARNING! Wear appropriate
protective eye gear during the clean-
ing process to prevent any eye injury
by the blown-off debris or liquid.
3. Check the main jet, pilot jet, and main
nozzle. Clean if there is dirt or residue.
NOTICE: Do not use steel wire for
cleaning the jets, otherwise the jet
diameters may be enlarged, which
may seriously affect performance
.
4. Check the pilot screw and needle valve.
Replace if there is bend or wear.
5. Check the float. Replace if there is crack
or deform.
6. Measure the float height
a
. Replace the
float or needle valve
1
, if out of specifi-
cation.
TIP:
9
Measure the float height when it is resting
on the needle valve
1
. Do not push down
on the float.
9
Take measurements at the top of the float
flange opposite its pivoted side.
Checking the Prime Start
1. Measure the length of the Prime Start
plunger.
2. Connect the positive Prime Start Blue (L)
lead and the negative Prime Start Black
(B) lead to a battery.
3. Measure the plunger length
a
after
applying power for 5 minutes. Replace if
below specification.
Float height
a
:
9.5–10.5 mm (0.37–0.41 in)
Prime Start plunger length before supply-
ing power (reference data):
20.5 mm (0.81 in) at 20 °C (68 °F)
1
a