Checking The Valve Seats - Yamaha V Star 950 Service Manual

Valve guide remover (ø6)
90890-04064
Valve guide remover (6.0 mm)
YM-04064-A
Valve guide installer (ø6)
90890-04065
Valve guide installer (6.0 mm)
YM-04065-A
Valve guide reamer (ø6)
90890-04066
Valve guide reamer (6.0 mm)
YM-04066
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
3. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
4. Check:
• Valve face
Pitting/wear → Grind the valve face.
• Valve stem end
Mushroom shape or diameter larger than
the body of the valve stem → Replace the
valve.
5. Measure:
• Valve margin thickness "a"
Out of specification → Replace the valve.
Valve margin
(intake)
1.00 mm (0.0394 in)
Valve margin
(exhaust)
1.00 mm (0.0394 in)
6. Measure:
• Valve stem runout
Out of specification → Replace the valve.
TIP
• When installing a new valve, always replace
the valve guide.
VALVES AND VALVE SPRINGS
• If the valve is removed or replaced, always
EAS24300

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
2. Check:
3. Measure:
thickness D
thickness D
5-27
replace the valve stem seal.
Valve stem runout
0.010 mm (0.0004 in)
• Carbon deposits
(from the valve face and valve seat)
• Valve seat
Pitting/wear → Replace the cylinder
head.
• Valve seat width "a"
Out of specification → Replace the cylin-
der head.
Valve seat width C (intake)
0.90–1.10 mm (0.0354–0.0433
in)
Limit
1.6 mm (0.06 in)
Valve seat width C (exhaust)
0.90–1.10 mm (0.0354–0.0433
in)
Limit
1.6 mm (0.06 in)