68
Disassembly/Inspection and Service
KohlerEngines.com
22 690 01 Rev. --
Valve Seat Inserts
Hardened steel alloy intake and exhaust valve seat
inserts are press fi tted into cylinder head. Inserts are
not replaceable, but they can be reconditioned if not too
badly pitted or distorted. If seats are 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 a 44.5° 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
valve face and seat.
Lapping Valves
Reground or new valves must be lapped in, to provide
a good seal. 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 engine 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.
Remove Breather
F
C
A
B
D
E
A
Breather Cover
Screw
B
Breather Cover
C
Torx Screw
D
Reed Retainer
E
Breather Reed
F
Breather Filter
NOTE: Breather cover is sealed to closure plate using
RTV silicone sealant. Once removed, cover
must be replaced. When removing breather
cover, use care not to damage sealing surface of
closure plate.
1. Remove screw securing breather cover to closure
plate; remove cover.
2. Remove Torx screw, reed retainer, and breather
reed.
3. Remove breather fi lter from closure plate.
Remove Closure Plate
B
A
C
A
Closure Plate Screw
B
Closure Plate
Assembly
C
Crankcase
NOTE: Closure plate is sealed to crankcase using RTV
silicone sealant. When removing closure plate,
use care not to damage sealing surface of
crankcase.
1. Remove screws securing closure plate to crankcase.
2. To break RTV seal, use a prying device and apply
pressure at corner of closure plate where breather is
located until RTV separates; then pull from corners
to remove closure plate assembly. Do not pry on
sealing surfaces of crankcase or closure plate, as
this can cause damage resulting in leaks.
Disassemble Closure Plate Assembly
B
A
C
A
Oil Passage Cover
B
Governor Gear
C
Oil Passage Cover
Screws
NOTE: Governor gear is held onto shaft by small
molded tabs in gear. When gear is removed
these tabs are destroyed and gear must be
replaced. Governor gear removal is required for
closure plate disassembly and cleaning of oil
passages. Unless bearings are being replaced,
they can stay in closure plate.