Yamaha MT-09 2021 - Page 259

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VALVES AND VALVE SPRINGS
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”.
b. Install the new valve guide with the valve
guide installer “2” and valve guide remover
“1”.
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.
TIP
After replacing the valve guide, reface the valve
seat.
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.
Valve guide position
13.3–13.7 mm (0.52–0.54 in)
G088960
G088961
G088962
a. Valve guide position
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
G088963
G088964