
'61HN252' by American Honda Motor Co. - Page 174 of 540
http://services.honda.com/ServiceManual/SVC_MNL/61HN253/61HN2...
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3/9/2008 10:50 PM
[2005-2008] [TRX500 FA/FGA]
CYLINDER HEAD/VALVE/CAMSHAFT
Subtract each valve stem O.D. from the correspond-
ing guide I.D. to obtain the stem-to-guide clearance.
SERVICE LIMITS: IN: 0.12 mm (0.005 in)
EX: 0.14 mm (0.006 in)
If the stem-to-guide clearance exceeds the service
Inspect and reface
limit, determine if a new guide with standard
the valve seats
dimensions would bring the clearance within toler-
whenever the valve
ance.
guides are replaced
If so, replace any guides as necessary and ream to
(page 8-14).
fit.
If the stem-to-guide clearance exceeds the service
limit with a new guide, also replace the valve.
VALVE GUIDE REPLACEMENT
Chill new valve guides in the freezer section of a
VALVE GUIDE DRIVER
refrigerator for about an hour.
Heat the cylinder head to 130--140°C (275--290°F)
Be sure to wear
with a hot plate or oven. Do not heat the cylinder
heavy gloves to
head beyond 150°C (300°F). Use temperature indica-
avoid burns when
tor sticks, available from welding supply stores, to
handling the heated
be sure the cylinder head is heated to the proper
cylinder head.
temperature.
Using a torch to
heat the cylinder
Support the cylinder head and drive the valve
head may cause
guides out of the cylinder head from the combus-
warpage.
tion chamber side.
TOOL:
Valve guide driver, 5.5 mm
07742-0010100
While the cylinder head is still heated, drive new
VALVE GUIDE DRIVER
valve guides in the cylinder head from the rocker
arm side using the same tool until the exposed
height is specified value.
VALVE GUIDE
VALVE GUIDE PROJECTION:
IN: 15.8-16.2 mm (0.62-0.64 in)
EX: 18.8-19.2 mm (0.74-0.76 in)
Let the cylinder head cool to room temperature.
Ream the new valve guides.
Take care not to tilt
REAMER
or lean the reamer
Insert the reamer from the combustion chamber
in the guide while
side of the head and always rotate the reamer clock-
reaming.
wise.
TOOL:
Valve guide reamer, 5.5 mm
07984-2000001 or
07984-200000D
(U.S.A. only)
Use cutting oil on the reamer during this operation.
Clean the cylinder head thoroughly to remove any
metal particles after reaming and reface the valve
seat
(page 8-14).
8-12