Yamaha 40V - Carburetor Assembly

4-10
FUEL
E
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.
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
Float height a:
15.0 ± 1.0 mm (0.59 ± 0.04 in)
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)