Valve Spring; Valve Seat - Yamaha TT-R50E Owner's Service Manual

VALVES AND VALVE SPRINGS

Valve spring

1. Measure:
2. Measure:

Valve seat

1. Measure:
Measurement steps:
• Apply Mechanic's blueing dye (Dykem) b
• Install the valve into the cylinder head.
• Press the valve through the valve guide
• Measure the valve seat width. Where the
• If the valve seat is too wide, too narrow, or
4 - 20
• Valve spring free length a
Out of specification → Replace.
Free length (valve spring):
Intake:
32.45 mm (1.28 in)
<Limit>: 30.83 mm (1.21 in)
Exhaust:
32.45 mm (1.28 in)
<Limit>: 30.83 mm (1.21 in)
• Spring tilt a
Out of specification → Replace.
Spring tilt limit:
Intake:
2.5°/1.4 mm (0.06 in)
Exhaust:
2.5°/1.4 mm (0.06 in)
• Valve seat width a
Out of specification → Reface the valve
seat.
Valve seat width:
Intake:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
<Limit>: 1.6 mm (0.0630 in)
Exhaust:
0.9 ~ 1.1 mm (0.0354 ~ 0.0433 in)
<Limit>: 1.6 mm (0.0630 in)
to the valve face.
and onto the valve seat to make a clear
pattern.
valve seat and valve face made contact,
blueing will have been removed.
the seat is not centered, the valve seat
must be refaced.
ENG