Installation - Yamaha PZ50W Service Manual

VALVES AND VALVE SPRINGS
12. Measure:
• Compressed valve spring force a
Out of specification → Replace the valve
spring.
b Installed length
13. Measure:
• Valve spring tilt a
Out of specification → Replace the valve
spring.
14. Inspect:
• Valve lifter
Damage/scratches → Replace the valve lift-
ers and cylinder head.

INSTALLATION

1. Deburr:
• Valve stem end
(with an oil stone)
5-38
ENG
Compressed valve spring force
(installed):
Intake:
120.7 ~ 138.9 N at 30.13 mm
(12.3 ~ 14.2 kg at 30.13 mm,
27.1 ~ 31.2 lb at 1.19 in)
Exhaust:
150.6 ~ 173.2 N at 30.50 mm
(15.4 ~ 17.7 kg at 30.50 mm,
33.9 ~ 38.9 lb at 1.20 in)
Maximum valve spring tilt:
Intake:
2.5°/1.6 mm (0.06 in)
Exhaust:
2.5°/1.7 mm (0.07 in)