Checking The Valve Lifter; Assembling The Cylinder Block - Yamaha F4B Service Manual

POWR
c
Cam lobe height a:
Intake:
32.037–32.137 mm
(1.2613–1.2652 in)
Exhaust:
32.038–32.138 mm
(1.2613–1.2653 in)
Cam lobe width b:
Intake and exhaust:
26.950–27.050 mm
(1.0610–1.0650 in)
Fuel pump cam diameter c:
19.600 mm (0.7717 in)
(reference data)
4. Measure the camshaft journal diameter
d.
d
Camshaft journal diameter d:
14.965–14.990 mm
(0.5892–0.5902 in)
5. Measure the camshaft runout.
7-45
Power unit
b
d
a
Camshaft runout: 0.030 mm (0.0012 in)

Checking the valve lifter

1. Check the valve lifter. Replace if dam-
aged or worn.
2. Measure the valve lifter outside diameter
a.
Valve lifter outside diameter a:
7.965–7.980 mm (0.3136–0.3142 in)

Assembling the cylinder block

Do not reuse an O-ring or oil seal, piston
pin clip, or bearing, always replace it with
a new one.
1. Install a new ball bearing a.
b
c
a
a