70
Disassembly/Inspection and Service
KohlerEngines.com 24 690 06 Rev. C
E
G
F
H
E
Fillet Must Blend Smoothly with Bearing Journal
Surface
F High Point from Fillet Intersections
G 45° Minimum
H This Fillet Area Must Be Completely Smooth
NOTE: If crankpin is reground, visually check to ensure
fi llet blends smoothly with crankpin surface.
Carefully pull crankshaft from crankcase. Note thrust
washers and shims if used.
Inspect gear teeth of crankshaft. If teeth are badly worn,
chipped, or some are missing, replacement of crankshaft
will be necessary.
Inspect crankshaft bearing surfaces for scoring,
grooving, etc. Some engines have bearing inserts in
crankshaft bore of closure plate and/or crankcase.
Do not replace bearings unless they show signs of
damage or are out of running clearance specifi cations. If
crankshaft turns easily and noiselessly, and there is no
evidence of scoring, grooving, etc., on races or bearing
surfaces, bearings can be reused.
Inspect crankshaft keyways. If they are worn or chipped,
replacement of crankshaft will be necessary.
Inspect crankpin for score marks or metallic pickup.
Slight score marks can be cleaned with crocus cloth
soaked in oil. If wear limits, as stated in Specifi cations
and Tolerances are exceeded, it will be necessary to
either replace crankshaft or regrind crankpin to 0.25 mm
(0.010 in.) undersize. If reground, a 0.25 mm (0.010 in.)
undersize connecting rod (big end) must then be used to
achieve proper running clearance. Measure crankpin for
size, taper, and out-of-round.
Connecting rod journal can be ground one size under.
When grinding a crankshaft, grinding stone deposits
can get caught in oil passages, which could cause
severe engine damage. Removing crankpin plug when
crankshaft is ground provides easy access for removing
any grinding deposits collected in oil passages.
Use following procedure to remove and replace plug.
Procedure to Remove Crankshaft Plug:
1. Drill a 3/16" hole through plug in crankshaft.
2. Thread a 3/4" or 1" long self-tapping screw with a fl at
washer into drilled hole. Flat washer must be large
enough to seat against shoulder of plug bore.
3. Tighten self-tapping screw until it draws plug out of
crankshaft.
Procedure to Install New Plug:
Use 1 single cylinder camshaft pin as a driver and tap
plug into plug bore until it seats at bottom of bore. Make
sure plug is tapped in evenly to prevent leakage.
Remove Governor Cross Shaft
1. Remove hitch pin and plain washer, or retainer and
nylon washer from governor cross shaft.
2. Pull cross shaft with small washer out through inside
of crankcase.
Governor Cross Shaft Oil Seal
Cross Shaft Oil Seal Details
B
A
A 2.0 mm (0.0787 in.)
B Governor Cross Shaft Seal
If governor cross shaft seal is damaged and/or leaks,
replace it using following procedure.
Remove oil seal from crankcase and replace it with a
new one. Install new seal to depth shown using a seal
installer.
Remove Flywheel End Oil Seal
Remove oil seal from crankcase.
Crankcase
Inspection and Service
Check all gasket surfaces to make sure they are free of
gasket fragments. Gasket surfaces must also be free of
deep scratches or nicks.
Inspect main bearing (if equipped) for wear or damage.
Replace crankcase using a miniblock or short block as
required.
Check cylinder bore wall for scoring. In severe cases,
unburned fuel can cause scuffi ng and scoring of cylinder
wall. It washes necessary lubricating oils off piston and
cylinder wall. As raw fuel seeps down cylinder wall,
piston rings make metal to metal contact with wall.
Scoring of cylinder wall can also be caused by localized
hot spots resulting from blocked cooling fi ns or from
inadequate or contaminated lubrication.
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