Checking The Cylinder Head; Checking The Rocker Arm; Checking The Push Rod; Checking The Valve Spring - Yamaha F4B Service Manual

Valve spring compressor b:
90890-04019
Valve spring compressor attachment c:
90890-06320
TIP:
Make sure to keep the parts in the order of
removal.
3. Remove the valve seals d.
d

Checking the cylinder head

1. Remove carbon deposits from the com-
bustion chamber, and then check the cyl-
inder head for corrosion or scratches.
2. Check the cylinder head warpage in 6
directions. Replace the cylinder head
assembly if above specification.
b
c
d
Cylinder head warpage limit:
0.10 mm (0.0039 in)

Checking the rocker arm

1. Check the rocker arms. Replace if
cracked, damaged, or worn.

Checking the push rod

1. Measure the push rod runout.
Push rod runout: 0.5 mm (0.02 in)

Checking the valve spring

1. Measure the valve spring free length a.
Cylinder head
0
1
2
3
4
5
6
7
8
9
10
A
7-30