Honda HRG416C1 Manual page 75

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CRANKSHAFT/PISTON/VALVES
GUIDE-TO-STEM CLEARANCE
Subtract each valve stem O.D. from the corresponding
guide I.D. to obtain the guide-to-stem clearance.
STANDARD:
IN: 0.020 – 0.047 mm (0.0008 – 0.0019 in)
EX: 0.060 – 0.087 mm (0.0024 – 0.0034 in)
SERVICE LIMIT:
IN: 0.10 mm (0.004 in)
EX: 0.12 mm (0.005 in)
If the calculated clearance is more than the service limit,
replace the valve and the cylinder (page 10-6).
VALVE SEAT WIDTH
Remove the carbon deposits from the combustion
chamber (page 3-7).
Inspect each valve face for irregularities.
If necessary, replace the valve(page 10-6).
Apply a light coat of Prussian Blue or erasable felt-
tipped marker ink to each valve seat.
Insert the valve, using a commercially available valve
lapper [1] and snap it closed against its seat several
times. Be sure the valve does not rotate on the seat.
The transferred marking compound will show any area
of the valve face that is not concentric.
Measure the valve seat width of the cylinder.
STANDARD:
SERVICE LIMIT: IN/EX: 1.8 mm (0.07 in)
If the measurement is more than the service limit,
recondition the valve seat.
Check whether the valve seat contact area of the valve
is too high or too low.
If the valve seat is too high or too low, recondition the
valve seat.
10-20
IN/EX: 0.7 – 0.9 mm (0.03 – 0.04 in)
VALVE SEAT
WIDTH
VALVE SEAT
WIDTH
[1]
VALVE SEAT
TOO HIGH
VALVE SEAT
TOO LOW