Engine Service Manual

72
Disassembly/Inspection and Service
KohlerEngines.com 32 690 03 Rev. I
Flywheel/Ignition/Breather Components
I
K
L
J
M
F
G
H
C
B
A
D
E
A Flywheel Screw B Fan
C Washer D Fan Mounting Plate
E Magnet F Flywheel
G Stator H Backing Plate
I Breather Reed Cover J Stud
K Retainer L Breather Reed
M Flywheel Key
Valve Seat Inserts
Hardened steel alloy intake and exhaust valve seat
inserts are press-fi tted into cylinder head. Inserts are
not replaceable but can be reconditioned if not too badly
pitted or distorted. If cracked or badly warped, cylinder
head should be replaced.
Recondition valve seat inserts following instructions
provided with valve seat cutter being used. Final cut
should be made with an 89° cutter as specifi ed for
valve seat angle. Cutting proper 45° valve face angle,
as specifi ed, and proper valve seat angle (44.5°, half of
full 89° angle), will achieve desired 0.5° (1.0° full cut)
interference angle where maximum pressure occurs on
outside diameters of valve face and seat.
Lapping Valves
NOTE: Exhaust valves that are black in color cannot be
ground and do not require lapping.
Reground or new valves must be lapped in, to provide
fi t. Use a hand valve grinder with suction cup for
fi nal lapping. Lightly coat valve face with fi ne grade
of grinding compound, then rotate valve on seat with
grinder. Continue grinding until smooth surface is
obtained on seat and on valve face. Thoroughly clean
cylinder head in soap and hot water to remove all traces
of grinding compound. After drying cylinder head, apply
a light coating of SAE 10 oil to prevent rusting.
Intake Valve Stem Seal
Always use a new seal when valves are removed
from cylinder head. Seals should also be replaced if
deteriorated or damaged in any way. Never reuse an old
seal.