Yamaha TMAX XP500F 2015, Service Manual, Page: 263 / 478

VALVES AND VALVE SPRINGS
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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.
6. Measure:
• Valve stem runout
Out of specification
→
Replace the valve.
TIP
• When installing a new valve, always replace
the valve guide.
• If the valve is removed or replaced, always re-
place the valve stem seal.
EAS30285
CHECKING THE VALVE SEATS
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
2. Check:
• Valve seat
Pitting/wear
→
Replace the cylinder head.
3. Measure:
• Valve seat width “a”
Out of specification
→
Replace the cylinder
head.
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a. Apply blue layout fluid “b” onto the valve face.
Valve guide remover (ø4)
90890-04111
Valve guide remover (4.0 mm)
YM-04111
Valve guide installer (ø4)
90890-04112
Valve guide installer (4.0 mm)
YM-04112
Valve guide reamer (ø4)
90890-04113
Valve guide reamer (4.0 mm)
YM-04113
Valve margin thickness (intake)
0.50–0.90 mm (0.0197–0.0354 in)
Valve margin thickness (exhaust)
0.50–0.90 mm (0.0197–0.0354 in)
Valve stem runout
0.040 mm (0.0016 in)
Valve seat contact width (intake)
0.90–1.10 mm (0.0354–0.0433 in)
Limit
1.6 mm (0.06 in)
Valve seat contact width (ex-
haust)
0.90–1.10 mm (0.0354–0.0433 in)
Limit
1.6 mm (0.06 in)