Honda CRF450R 2009 Service Manual page 269

INTAKE SIDE:
After refaclng, wash the cylinder head and valves,
I
NOTICE
I
Do
not lap the intake valves. They are titanium and
have
8
thin oxide coating. Lappmg will damage this
coatmg.
Use the mtake valve
as a
new one.
EXHAUST SI DE:
After cutting the exhaust seats , apply lapping
compound to the exhaust valve face, and lap the
exhaust valve using light pressure .
After lapping, wash any residual compound off the
cylinder head and valves.
I
NOTICE
I
ExceSSIVe lapping pressure may deform or damage
the
seat.
Change the angle of the lapping tool frequently to
prevent uneven
seal
wear.
Do
not allow any lapping compound to enter the
guides.
CYLINDER HEAD ASSEMBLY
'09· " 4 shown·
VALVE COTTERS
~
SPRING RETAINER
/ '!.
~ SPRING~ ~
S
STEM SEAL ____
- ~ ~
SPRING SEAT _ _ _ _ _ _
...:.~ ~
CYLINDER HEADNALVES
INTAKE VALVE
~
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