Checking The Valve Springs; Checking The Valves - Yamaha F15B Service Manual

POWR
6. Remove the intake valve and exhaust
valves.
6
5
NOTE:
When replacing the valve, also replace the
valve guide and stem seal.
Valve spring compressor 5:
90890-04019
Valve spring compressor
attachment 6:
90890-06320

Checking the valve springs

1. Measure the valve spring free length a.
Replace if out of specification.
Valve spring free length a:
34.40 mm (1.3543 in)
5-25
Power unit
6D450540
a
6D450550
2. Measure the valve spring tilt b. Replace
if out of specification.
Valve spring tilt limit b:
1.5 mm (0.06 in)

Checking the valves

1. Check the valve face for pitting or wear.
Replace if necessary.
2. Measure the valve margin thickness a.
Replace if out of specification.
Valve margin thickness a:
Intake:
0.50–0.90 mm (0.0197–0.0354 in)
Exhaust:
0.50–0.90 mm (0.0197–0.0354 in)
b
6D450560
a
6D450570
6D45F11