Install New Piston Rings; Piston Ring Orientation - Kohler command CH18 Service Manual

Piston Style B
1. Cylinder bore must be de-glazed before service ring
sets are used.
2. If cylinder bore does not need re-boring and if old
piston is within wear limits and free of score or scuff
marks, old piston may be reused.
3. Remove old rings and clean up grooves. Never
reuse old rings.
4. Before installing new rings on piston, place top 2
rings, each in turn, in its running area in cylinder
bore and check end gap.
80 mm bore engines: Top compression ring end gap
clearance is 0.100/0.279 mm (0.0039/0.0110 in.) for
a new bore, or 0.490 mm (0.0192 in.) for a used
bore. Middle compression ring end cap is
1.400/1.679 mm (0.0551/0.0661 in.) for a new bore,
or 1.941 mm (0.0764 in.) for a used bore.
83 mm bore engines: Top compression ring end gap
clearance is 0.189/0.277 mm (0.0074/0.0109 in.) for
a new bore, or 0.531 mm (0.0209 in.) for a used
bore. Middle compression ring end cap is
1.519/1.797 mm (0.0598/0.0708 in.) for a new bore,
or 2.051 mm (0.0808 in.) for a used bore.
5. After installing new compression (top and middle)
rings on piston, make sure top compression ring-to-
groove side clearance and is 0.030/0.070 mm
(0.0010/0.0026 in.) and middle compression ring-to-
groove side clearance 0.030/0.070 mm
(0.0010/0.0026 in.). If side clearance is greater than
specified, a new piston must be used.
24 690 06 Rev. J
Disassembly/Inspection and Service

Install New Piston Rings

Piston Ring Orientation

A
10°
10°
B
Top Oil Ring Rail
A
Intermediate Ring
C
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 first 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 identification 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
identification mark is up or colored dye stripe
(if contained), is to left of end gap.
KohlerEngines.com
E
F
C
Bottom Oil Ring Rail
B
Gap
Oil Ring Expander
D
Gap
F
D
Gap
Gap
FLY Stamp
71