Yamaha F4B, Service Manual

Page: 86 / 202

6-19
FUEL
Fuel system
5. Check the needle valve. Replace if
deformed or worn.
6. Check the float. Replace if cracked or
deformed.
Assembling the carburetor
Do not reuse an O-ring or gasket, always
replace it with a new one.
1. Install the main nozzle
a
and main jet
b
.
2. Install the needle valve
c
, clip
d
, and
float
e
.
3. Install the float pin
f
to the specified
installation position
a
.
4. Install the spring
g
.
5. Measure the float height
b
. Adjust the
float height by bending the tab
c
if out of
specification.
TIP:
When measuring the float height
b
hold the
carburetor body at angle of 45° so that there
is no load on the needle valve spring.
6. Install a new gasket
h
, the float chamber
i
, a new O-ring
j
, and the drain screw
k
.
a
b
c
d
e
f
g
Position
a
: 1.0 mm (0.04 in)
Float height
b
(reference data):
10.0 mm (0.4 in)
a
f
g
c
b
e
45°