Service Manual

PERIODIC MAINTENANCE 2-11
Periodic Maintenance Procedures
Marks Stamped on the Cutter:
The m arks stamped on the back of the cutter represent the
following.
1 Cutter number, selected from 1 to 12
30
Cutter angle [A]
37.5 Cutter diameter of cutter [B]
KS8B Manufactured lot number
Operating Procedures:
•
Clean the seat area carefully.
•
Recondition the valve seats with the valve seat cutters
(45
,32) and lap the valves.
•
Check the seats for good contact all the way around with
machinist’s dye.
•
Measure the seat width [A]. If it is more than the STD
width, the seating surface should be refaced.
•
If the valve seating pattern is not correct, repair the seat.
•
Coat the seat with machinist’s dye.
•
Fit a 45 seat cutter [A] to the holder and slide it into the
valve guide.
Resurface the valve seat with a 45 cutter, removing only
enough material to produce a smooth and concentric
seat.
CAUTION
Do not grind the seat too much. Overgrinding will
reduce valve clearance by sinking the valve into the
head. If the valve sinks too far into the head, it will
be impossible to adjust the clearance, and the cylin-
der head m ust be replaced. Do not turn the cutter
counterclockwise or drop it against the seat, or it
will be dulled.