BRP Johnson J30TEL4SUA 2007 Service Manual page 147

The service limit for valve head radial runout is
0.003 in. (0.08 mm). If the measurement exceeds
this specification, replace the valve.
Use vernier calipers to measure the thickness of
the valve head.
If the measurement exceeds the service limit,
replace the valve.
Valve Head Thickness
IN
Standard
EX
IN
Service Limit
EX
001496
0.04 in. (1.0 mm)
0.05 in. (1.3 mm)
0.02 in. (0.5 mm)
0.03 in. (0.7 mm)
001497
Measure the valve seat contact width as follows:
•
Remove all carbon deposits from the valve and
the valve seat.
•
Coat the valve seat evenly with Prussian blue
(or equivalent).
•
Install the valve into the valve guide.
•
Place a valve lapper on the valve.
•
Rotate the valve while gently tapping the valve
contact area against the seat. Repeat until a
continuous pattern in the Prussian Blue is seen.
Use vernier calipers to measure the valve seat
contact width.
If the measurement exceeds the specification,
reface the valve seat.
Valve Seat Contact Width
Intake valve 0.05 – 0.06 in. (1.3 – 1.5 mm)
Exhaust valve 0.05 – 0.06 in. (1.3 – 1.5 mm)
POWERHEAD
CYLINDER HEAD
001498
001499
145
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