Kohler K9J Service Manual page 113

Some important points to remember when servic-
ing piston rings:
1 . If the cylinder block does not need reboring
and if the old piston is within wear limits (refer
to Section 1 , "General Information") and free
of score or scuff marks, the old piston may be
reused.
2. Remove old rings and clean up grooves. Never
reuse old rings.
3. Before installing new rings on piston, place top
two rings, each in turn, into its running area in
cylinder bore and check end gap (see Figure
11-11).
Model
K91, K161,
K181
K241, K301,
K321, K341
End Gap
New
Used
.007/.017* .007/.027*
.010/.020 .010/.030
*On Model K181 using piston style C or D,
New .010/.023, Used .010/.032.
Figure 11-11. Measuring Piston Ring End Gap.
4. After installing the new compression (top and
middle) rings on piston, check piston-to-ring
side clearance. Maximum recommended side
clearance is .006". If side clearance is greater
than .006", a new piston must be used. Refer
to Figure 11-12.
11.10
Figure 11-12. Measuring Piston Ring Side
Clearance.
Oil Ring End Gaps
Although 4 sizes of service ring sets are available
(Std., +-.01 0", +-.020, +-.030"), only two sizes
of oil rings are supplied (Std. and .020" oversize).
When using .010" and .030" oversize ring sets,
the oil rings appear to have excessive end gap.
This is not detrimental and proper sealing will be
achieved due to the additional scraper rings and
expander.
NOTE: Scraper and main ring end gaps should be
staggered around the groove to prevent combus-
tion blow-by.
Install Piston Rings
NOTE: Rings must be installed correctly. Ring in-
stallation instructions are usually included with new
ring sets. Follow instructions carefully. Use a pis-
ton ring expander to inStall rings. Install the bottom
(oil control) ring first and the top compression ring
last.
POSI-LOCK CONNECTING RODS
Posi-Lock connecting rods are used in some K-
Series engines. On model K181 engines with the
style D pistons (refer to "Piston and Rings, Identifi-
cation" earlier in this section), the connecting rods
have a narrower piston pin end than on the earlier
(style A) Posi-Lock connecting rods (refer to Fig-
ure 11-13). Therefore, the Posi-Lock connecting
rods used with the style D pistons' are not inter-
changeable with the Posi-Lock connecting rods
used with style A pistons.