Checking The Crankcase; Checking The Rotor Assembly - Yamaha F4B Service Manual

3. Loosen the crankcase bolts d in the
order a, b, and so on, and then remove
the crankcase e, gasket f, and dowels
g.
f
j
g
d
h
i
d

Checking the crankcase

1. Check the crankcase. Replace if cor-
roded or cracked.
2. Measure the crankshaft journal inside
diameter a.
3. Measure the camshaft journal inside
diameter b.
d
e
c
b
a
e
g
f
a
Crankshaft journal inside diameter a:
25.020–25.041 mm
(0.9850–0.9859 in)
Camshaft journal inside diameter b:
15.000–15.018 mm
(0.5906–0.5913 in)
4. Measure the rotor
diameter c.
c
Rotor housing inside diameter c:
23.130–23.160 mm
(0.9106–0.9118 in)

Checking the rotor assembly

1. Check the rotor assembly. Replace if
cracked or worn.
2. Measure the rotor assembly dimensions
a, b, and c.
c
Crankcase
b
housing inside
a
10
b
7-24
0
1
2
3
4
5
6
7
8
9
A