83
Disassembly/Inspection and Service
66 690 14 Rev. A
KohlerEngines.com
Install New Piston Rings
Piston Ring Orientation
10°
10°
F
A
B
C
D
E
A
Top Oil Ring Rail
Gap
B
Bottom Oil Ring Rail
Gap
C
Intermediate Ring
Gap
D
Oil Ring Expander
Gap
E
Top Ring Gap
F
FLY Stamp
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 identi
fi
cation mark is up or dye colored stripe (if
contained) is to left of end gap.
3. Top compression ring (top groove): Install top ring
using a piston ring expender. Make sure
identi
fi
cation mark is up or dye colored stripe (if
contained), left of end gap.
Connecting Rods
O
ff
set, stepped-cap connecting rods are used in all
these engines.
Inspection and Service
Check bearing area (big end) for excessive wear, score
marks, running and side clearances. Replace rod and
cap if scored or excessively worn.
Service replacement connecting rods are available in
STD crankpin size and 0.25 mm (0.010 in.) undersize.
Always refer to appropriate parts information to ensure
correct replacements are used.
Remove Crankshaft
Carefully pull crankshaft from crankcase.
Inspection and Service
Crankshaft Components and Details
A
B
C
D
A
Self-Tapping Screw
B
Flat Washer
C
Plug
D
Crankshaft
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