Kohler LH630-775 Service Manual page 130

Section 10
Inspection and Reconditioning
NOTE: If the crankpin is reground, visually check to
ensure that the fillet blends smoothly with
the crankpin surface. See Figure 10-1.
High Point From
Fillet Intersections
The Fillet Must
Blend Smoothly
With The Bearing
45°
Journal Surface
Minimum
This Fillet
Area Must Be
Completely Smooth
Figure 10-1. Crankpin Fillets.
When grinding a crankshaft, grinding stone deposits
can get caught in oil passages which could cause
severe engine damage. Removing the crankpin plug
each time the crankshaft is ground provides easy
access for cleaning any grinding deposits that may
collect in the oil passages.
Use the following procedure to remove and replace
the plug.
Procedure to Remove Crankshaft Plug:
1. Drill a 3/16" hole through the plug in the
crankshaft.
2. Thread a 3/4" or 1" long self-tapping screw with
a flat washer into the drilled hole. The flat
washer must be large enough to seat against the
shoulder of the plug bore. See Figure 10-2.
1 2 3 4 5 6 7
1 2 3 4 5 6 7
1 2 3 4 5 6 7
1 2 3 4 5 6 7
Figure 10-2. Removing Crankpin Plug.
10.2
Self-Tapping Screw
Flat Washer
Plug
Crankshaft
3. Tighten the self-tapping screw until it draws the
plug out of the crankshaft.
Procedure to Install New Plug:
1. Use a single cylinder camshaft pin, Kohler Part
No. 47 380 09-S, as a driver and tap the plug into
the plug bore until it seats at the bottom of the
bore. Make sure the plug is tapped in evenly to
prevent leakage.
Crankcase
These engines contain a cast-iron cylinder liner that
may be reconditioned as follows:
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 the main bearing (if so equipped) for wear or
damage (refer to Section 1, "Specifications, Tolerances,
and Special Torque Values"). Replace the crankcase
using a mini-block or short block if required.
Check the cylinder bore for scoring. In severe cases,
unburned fuel can cause scuffing and scoring of the
cylinder wall. It washes the necessary lubricating oils
off the piston and cylinder wall. As raw fuel seeps
down the cylinder wall, the piston rings make metal
to metal contact with the wall. Scoring of the cylinder
wall can also be caused by localized hot spots
resulting from a cooling system problem or from
inadequate or contaminated lubrication.
If the cylinder bore is badly scored, excessively worn,
tapered, or out-of-round, resizing is necessary. Use an
inside micrometer to determine amount of wear (refer
to the "Specifications, Tolerances, and Special Torque
Values", in Section 1), then select the nearest suitable
oversize of either 0.08 mm (0.003 in.), 0.25 mm
(0.010 in.), or 0.50 mm (0.020 in.). Resizing to one of
these oversizes will allow usage of the available
oversize piston and ring assemblies. Initially, resize
using a boring bar, then use the following procedures
for honing the cylinder.
NOTE: If the bore is beyond the wear limit, a new
miniblock or short block will be required.