Valve Spring Inspection; Valve Lifter Inspection - Yamaha YZ250F(R) Owner's Service Manual

VALVES AND VALVE SPRINGS
Valve spring
1. Measure:
2. Measure:
b Installed length
3. Measure:
Valve lifter
1. Inspect:
4 - 39
Valve spring free length a
G
Out of specification → Replace.
Free length (valve spring):
Intake:
37.81 mm (1.49 in)
<Limit>: 35.9 mm (1.41 in)
Exhaust:
37.54 mm (1.48 in)
<Limit>: 35.7 mm (1.41 in)
Compressed spring force a
G
Out of specification → Replace.
Compressed spring force:
Intake:
99 ~ 114 N at 29.13 mm
(9.9 ~ 11.4 kg at 29.13 mm,
22.27 ~ 25.57 lb at 1.15 in)
Exhaust:
126 ~ 144 N at 29.30 mm
(12.6 ~ 14.4 kg at 29.30 mm,
28.44 ~ 32.41 lb at 1.15 in)
Spring tilt a
G
Out of specification → Replace.
Spring tilt limit:
Intake:
2.5˚/1.7 mm (0.067 in)
Exhaust:
2.5˚/1.6 mm (0.063 in)
Valve lifter
G
Scratches/damage → Replace both lift-
ers and cylinder head.
ENG