Honda 2005 CRF250X - Valve;Valve Guide

CYLINDER HEADIV ALVES
VALVEIVALVE GUIDE
Inspect each valve for out-af-r ound , burns ,
scratches
or abnorma l stem wear.
Check the valve movement in the gui d e.
Measu re an d record the valve stem 0. 0.
STANDARD:
IN : 4.975 - 4.990 mm (0.1959 - 0.1965 in)
EX : 4.965 - 4.980 mm (0.1955 - 0.1961 in)
SERVICE LIMIT :
EX : 4.955 mm (0.1951 in)
Ream the valve guide to remove any carbon buitd -
up before measuring the guide.
Inse rt the reamer from the co mbus ti on ch amber
side of the head and always rotate the reamer clock-
wise.
TOOL :
Valve guide reamer , 5.0 mm
07984·MA60001 or
07984-MA6000D
(U .S.A. only)
Measure and record each valve guide 1 .0 . using a
ball gauge or inside micrometer.
SERVICE LIMITS:
IN / EX : 5.052 mm (0.1989 in)
Subtract each valve stem
0 .0 . from the correspond -
ing guide 1.0. to obtain the stem - to-guide clearance.
STANDARD:
IN : 0.010 - 0.037 mm (0. 0004 - 0.0015 in)
EX : 0.020 - 0.047 mm (0. 0008 - 0.0019 in)
Reface the valve If th e stem-Io-guide clearance exceeds the service
sealS whentwBr the l imits, determine if a new guide with st andard
valve guides are dimensions would br ing the clearance within toler -
replaced (page 8- ance. If so, replace the guides as necessary and
8-18
19) ream to fit.
If the stem·to-guide clearance exceeds the service
limits with new guides also, replace the valves and
guides.
VALVE GUI DE RE~'i!. ~ ~