Carburetor Assembly - Yamaha 40V Service Manual

FUEL
CARBURETOR

Carburetor assembly

1. Install:
Needle valve
Float 1
Float pin 2
Screw 3
NOTE:
The float pin should be fit in the slit the
carburetor and locked with the screw.
When installing the float in the carburetor,
place the needle valve in the valve seat.
After installing, check the smooth move-
ment of the float.
2. Measure:
Float height a
Out of specification → Fold the tab b
to adjust float arm height.
Float height a:
15.0 ± 1.0 mm (0.59 ± 0.04 in)
NOTE:
The float should be resting on the needle
valve, but not compressing the needle
valve.
Take measurement at the end surface of
the float opposite to its pivoted side.
3. Adjust:
Pilot screw
Adjustment steps:
Screw in the pilot screw until it is
lightly seated
Back out by the specified number of
turns.
Pilot screw:
40hp: 1-1/2 ± 1/4 (turns out)
50hp:
M model: 1-5/8 ± 1/4 (turns out)
E, EM model: 1-3/8 ± 1/4 (turns out)
4-10
E