Yamaha MT-09 2021 Service Manual page 259

G088960
G088961
2. Replace:
• Valve guide
TIP
To ease valve guide removal and installation,
and to maintain the correct fit, heat the cylinder
head to 100 °C (212 °F) in an oven.
a. Remove the valve guide with the valve
guide remover "1".
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b. Install the new valve guide with the valve
guide installer "2" and valve guide remover
"1".
Valve guide position
13.3–13.7 mm (0.52–0.54 in)
VALVES AND VALVE SPRINGS
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a. Valve guide position
c. After installing the valve guide, bore the
valve guide with the valve guide reamer "3"
to obtain the proper valve-stem-to-valve-
guide clearance.
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TIP
After replacing the valve guide, reface the valve
seat.
Valve guide remover (ø4.5)
90890-04116
Valve guide remover (4.5 mm)
YM-04116
Valve guide installer (ø4.5)
90890-04117
Valve guide installer (4.5 mm)
YM-04117
Valve guide reamer (ø4.5)
90890-04118
Valve guide reamer (4.5 mm)
YM-04118
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.
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