Service Manual

5-10 ENGINE TOP END
Valves
Valve Clearance Inspection

Refer to Valve Clearance Inspection in the Periodic Maintenance
Chapter (2nd chapter).
Valve Clearance Adjustment

Refer to Valve Clearance Adjustment in the Periodic Maintenance
Chapter (2nd chapter).
Valve Seat Inspection

Refer to Valve Seat Inspection in the Periodic Maintenance Chapter
(2nd chapter).
Valve Seat Repair

Refer to Valve Seat Repair in the Periodic Maintenance Chapter (2nd
chapter).
Valve Head Thickness
•
Remove the valve (see Valve Mechanism Removal/Installation).
•
Measure the thickness of the valve head.
If the valve head thickness (valve margin) [A] is less than the service
limit, replace the valve.
Valve Head Thickness
Service Limit (IN, EX): 0.35 mm (0.014 in)
Valve Stem Runout
•
Support the valve in V blocks at each end of the stem.
•
Position a dial gauge perpendicular to the stem.
•
Turn the valve and read the variation on the dial gauge.
If the stem runout is greater than service limit, replace the valve.
Valve Stem Runout
Service Limit (IN, EX): 0.05 mm (0.002 in.)
Valve Stem Diameter
•
Measure the diameter of the valve stem [A] in two directions at right
angles, at four different positions on the stem.
If any single measurement is less than the service limit, replace the
valve.
Valve Stem Diameter
Service Limit:
Intake: 5.95 mm (0.234 in.)
Exhaust: 5.93 mm (0.233 in.)
Valve Guide Inside Diameter
•
Use a small bore gauge or a micrometer to measure the inside
diameter [A] of the valve guide [B] at three places down the length of
the guide.
If the measurement is more than the service limit, replace the cylinder
head with a new one.
Valve Guide Inside Diameter
Service Limit:
Intake, Exhaust 6.08 mm (0.239 in.)