Yamaha F25A - Valve Spring Inspection

5-25
POWR
E
CAMSHAFT AND VALVES
5. Measure:
● Valve stem runout
Out of specification → Replace the
valve.
NOTE:
When replacing the valve always use a new
valve guide and valve seal.
Valve stem runout limit:
0.016 mm (0.0006 in)
Valve spring inspection
1. Measure:
● Valve spring free length a
Out of specification → Replace the
valve spring.
Valve spring free length:
37.85 ~ 39.85 mm
(1.491 ~ 1.569 in)
2. Measure:
● Valve spring tilt a
Out of specification → Replace the
valve spring.
Valve spring tilt limit:
1.7 mm (0.06 in)