Honda CRF50F 2004-2015 Service Manual page 88

CYLINDER HEADIV ALVES
Ream the new valve guide after installation.
Use CUtting 011 on Insert the reamer from the combustion chamber
the reamerdunng
side of the head and always rotate the reamer
clock- "I!!""""-!~!"'''''!~
/hls opera/J()(I
wise.
r
TOOL:
Valve guide reamer, 5.0 mm 07984-MA60001
or
01984·MA60000
(U.S.A. only)
Clean the cylinder head thoroughly to remove any
metal particles.
Refaee the valva seat (page 7. 12).
VALVE SEAT INSPECTION/REFACING
Clean the intake and exhaust valves thoroughly to
~""!I.!:':~ND- I-A1!!NGi'6~~ ~
.......
remove carbon deposits.
~
The valves cannof
be
ground
If 8
valve
face is burned or
Apply a light coali ng of Prussian Blue t o the valve
seat. lap the
valves
and seats using a rubber hose
or other hand-lapping 1001.
Remove and inspect the valves.
Inspect the width of each valve seat.
badlywom 01 rf
If
STANDARD: 1.0 _ 1.3 mm (0.04 - 0.05 in)
COOfacrs rM sear SERVICE LIMIT: 2.0 mm (0.08 in)
uneven/),. replace
rhe valve. If the seat is 100 wide, 100 narrow or has low spots,
the seat must be ground.
VALVE SEAT REFACING
t
t
//
\
./
1.0-1.3
mm
(0.04 - 0.05 in)
• Follow the refacing manufacturer's operating , - - - - - - - - - - - - - - - - - - ,
instructions .
• Be careful nOI to
grind the seat more than neces·
say.
7-12
g \
45
0
6L'~20
6
\ 60
0