Honda SH300 2009 User Manual

CYLINDER HEAD/VALVES
9-13
VALVE SPRING
Check the valve springs for fatigue or damage.
Measure the valve spring free length.
VALVE/VALVE GUIDE
Check that the valve moves smoothly in the guide.
Check the valves for bending, burning or abnormal
wear.
Measure each valve stem O.D. and record it.
Ream the guides to remove any carbon build-up
before measuring the guide.
Insert the reamer from the combustion chamber
side of the head and always rotate the reamer clock-
wise.
Measure each valve guide I.D. and record it.
Subtract each valve stem O.D. from the correspond-
ing guide I.D. to obtain the stem-to-guide clearance.
If the stem-to-guide clearance exceeds the service
limit, determine if a new guide with standard
dimensions would bring the clearance within toler-
ance. If so, replace any guides as necessary and
ream to fit.
If the stem-to-guide clearance exceeds the service
limit with a new guide, also replace the valve.
SERVICE LIMIT: IN/EX: 35.6 mm (1.40 in)
SERVICE LIMITS:IN: 4.465 mm (0.1758 in)
EX: 4.455 mm (0.1754 in)
TOOL:
Valve guide reamer, 4.5 mm 07HMH-ML00101
VALVE GUIDE
REAMER
SERVICE LIMIT: IN/EX: 4.54 mm (0.179 in)
SERVICE LIMITS:IN: 0.08 mm (0.003 in)
EX: 0.09 mm (0.004 in)
Inspect and reface
the valve seats
whenever the valve
guides are replaced
(page 9-15).
VALVE GUIDE

Honda SH300 2009 Specifications

General

Displacement	279.1 cc
Bore x Stroke	72 mm x 68.5 mm
Compression Ratio	10.5:1
Fuel System	PGM-FI electronic fuel injection
Front Tire	110/70-16
Rear Tire	130/70-16
Width	730 mm
Height	1, 195 mm
Wheelbase	1, 420 mm
Engine Type	Liquid-cooled, 4-stroke, single-cylinder
Max Torque	26.5 Nm @ 6, 000 rpm
Transmission	V-Matic
Front Suspension	Telescopic fork, 35 mm
Rear Suspension	Twin shock absorbers
Front Brake	256mm hydraulic disc
Rear Brake	240 mm disc