Kohler ECV940 Service Manual page 139

5. After installing new compression (top and middle)
rings on piston, make sure ring-to-groove side
clearance is 0.04/0.08 mm (0.0015/0.0031 in.). If
side clearance is greater than specifi ed, a new
piston must be used.
Install New Piston Rings
Piston Ring Orientation
F
A
10°
10°
B
Top Oil Ring
A
Rail Gap
Middle Ring
C
Gap
E Top Ring Gap
NOTE: Rings must be installed correctly. Ring
installation instructions are usually included with
new ring sets. Follow instructions carefully. Use
a piston ring expander to install rings. Install
bottom (oil control) ring fi rst and top
compression ring last.
To install new piston rings, proceed as follows:
1. Oil control ring (bottom groove): Install expander and
then rails. Make sure ends of expander are not
overlapped.
2. Middle compression ring (center groove): Install
center ring using a piston ring installation tool. Make
sure identifi cation mark is up or colored dye stripe (if
contained), is to left of end gap.
3. Top compression ring (top groove): Install top ring
using a piston ring expander. Make sure
identifi cation mark is up or colored dye stripe (if
contained), is to left of end gap.
62 690 05 Rev. H
E
D
C
Bottom Oil Ring
B
Rail Gap
Oil Ring
D
Expander Gap
F FLY Stamp
KohlerEngines.com
Disassembly/Inspection and Service
Remove Crankshaft
NOTE: If crankpin is reground, visually check to ensure
that fi llet blends smoothly with crankpin surface.
Carefully pull crankshaft from crankcase. Note thrust
washers and shims if used.
Inspection and Service
Crankshaft Components and Details
A Self-Tapping Screw
C Plug
G
E
Fillet Must Blend Smoothly with Bearing Journal
E
F High Point from Fillet Intersections
G
H This Fillet Area Must Be Completely Smooth
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. A replaceable bearing is used in
crankshaft bore of oil pan. Do not replace bearing unless
it shows signs of damage, or is out of running clearance
0.040/0.167 mm (0.0015/0.0065 in.). If crankshaft turns
easily, without noise, and there is no evidence of scoring,
grooving, etc., on races or bearing surfaces, bearing can
be reused.
Inspect crankshaft keyways. If they are worn or chipped,
replacement of crankshaft will be necessary.
A
B
C
D
B Flat Washer
D Crankshaft
F
H
Surface
45° Minimum
139