Yamaha YZF-R7 Owner's Service Manual page 157

VALVES AND VALVE SPRINGS
2. Replace:
3. Eliminate:
4. Check:
4 - 25
• valve guide
NOTE:
To ease valve guide removal and instal-
lation, and to maintain the correct fit,
heat the cylinder head to 100 ˚C (212 ˚F)
in an oven.
a. Remove the valve guide with a 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 a valve guide
reamer 3 to obtain the proper valve
stem-to-valve guide clearance.
NOTE:
After replacing the valve guide, reface
the valve seat.
Valve guide remover
Intake (4.0 mm)
90890-04111
Valve guide installer
Intake (4.0 mm)
90890-04112
Valve guide reamer
Intake
90890-04113
• carbon deposits
(from the valve face and valve seat)
• 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.
ENG