Kohler Command PRO CS Service Manual page 124

Section 10
Internal Components
Install Piston Rings
To install piston rings, proceed as follows:
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 the bottom (oil control)
ring first and the top compression ring last.
Top Ring
2nd Ring
(Has R Marking)
Oil Ring
1. Oil Control Ring (Bottom Groove): Place the
expander in the lowest groove. The ends of the
expander must butt. Do not allow the ends to
overlap; incorrect tension and a loss of oil control
will result.
Place one end of a rail between the upper side of
the expander and groove, and ''wind'' into
position. Be careful that the end of rail does not
scratch the piston. Repeat this procedure with the
second rail on the lower side of the expander.
Position rail gaps 90° from the expander gap and
180° from each other. Check the assembly to ensure
freedom of movement in the groove. See Figure
10-16.
Install Top Rail in
This Direction Over
Expander Gap
Start Rail as
Indicated
Expander Gap
Figure 10-16. Oil Control Ring Details.
10.12
Expander Gap
Install Top Rail in This
Direction Over
Expander Gap
Start Rail as
Indicated
Expander Gap
2. Middle Compression Ring: Locate and identify
the compression ring with the R marking. Using
a piston ring expander, install this ring in the
middle groove with the R up towards the top of
the piston. See Figure 10-17.
Figure 10-17. Middle Compression Ring.
3. Top Compression Ring: Using a piston ring
expander, install the compression ring, with no
markings, into the top groove. It is symmetrical in
design, so it may be installed with either side up.
4. Stagger/position the two compression rings, so
the end gaps are spaced 120° apart, as well as
from the expander gap. See Figure 10-18.
120°
4
Figure 10-18. Ring Gap Positioning.
Connecting Rods
Inspection and Service
Check bearing area (big end) for excessive wear, score
marks, running and side clearances (Refer to Section
1, Specifications, Tolerances, and Special Torque
Values). Replace rod if scored or excessively worn.
2
120°
3
120°