Kohler COMMAND CH18-745 - Piston, Piston Rings, and Piston Pin Specifications

1.12
Section 1
Safety and General Information
²Measure 6 mm (0.236 in.) above the bottom of the piston skirt at right angles to the piston pin.
Muffler
Muffler Retaining Nut Torque .................................................................. 24.4 N·m (216 in. lb.)
Oil Filter
Oil Filter Torque .................................................................................... 10.4-12.7 N·m (90-110 in. lb.)
Oil Cooler
Oil Cooler/Adapter Nipple Torque ......................................................... 27 N·m (20 ft. lb.)
Piston, Piston Rings, and Piston Pin
Piston-to-Piston Pin Running Clearance ............................................... 0.006/0.017 mm (0.0002/0.0007 in.)
Piston Pin Bore I.D.
New................................................................................................ 17.006/17.012 mm (0.6695/0.6698 in.)
Max. Wear Limit ............................................................................. 17.025 mm (0.6703 in.)
Piston Pin O.D.
New................................................................................................ 16.995/17.000 mm (0.6691/0.6693 in.)
Max. Wear Limit ............................................................................. 16.994 mm (0.6691 in.)
Top Compression Ring-to-Groove Side Clearance
CH18, CH20, CH22 (624 cc).......................................................... 0.040/0.080 mm (0.0016/0.0031 in.)
CH22/23 (674 cc) ........................................................................... 0.030/0.076 mm (0.0012/0.0030 in.)
CH25, CH26, CH730-745............................................................... 0.025/0.048 mm (0.0010/0.0019 in.)
Middle Compression Ring-to-Groove Side Clearance
CH18, CH20, CH22 (624 cc).......................................................... 0.040/0.080 mm (0.0016/0.0031 in.)
CH22/23 (674 cc) ........................................................................... 0.030/0.076 mm (0.0012/0.0030 in.)
CH25, CH26, CH730-745............................................................... 0.015/0.037 mm (0.0006/0.0015 in.)
Oil Control Ring-to-Groove Side Clearance
CH18, CH20, CH22 (624 cc).......................................................... 0.060/0.202 mm (0.0024/0.0080 in.)
CH22/23 (674 cc) ........................................................................... 0.046/0.196 mm (0.0018/0.0077 in.)
CH25, CH26, CH730-745............................................................... 0.026/0.176 mm (0.0010/0.0070 in.)
Top and Center Compression Ring End Gap
New Bore - CH18, CH20, CH22 (624 cc) ....................................... 0.25/0.45 mm (0.0098/0.0177 in.)
New Bore - CH22 (674 cc) ............................................................. 0.18/0.46 mm (0.0071/0.0181 in.)
New Bore - CH25, CH26, CH730-745 ............................................ 0.25/0.56 mm (0.0100/0.0224 in.)
Used Bore (Max.) - CH18, CH20, CH22 (624 cc)........................... 0.77 mm (0.030 in.)
Used Bore (Max.) - CH22/23 (674 cc) ............................................ 0.80 mm (0.0315 in.)
Used Bore (Max.) - CH25, CH26, CH730-745 ............................... 0.94 mm (0.037 in.)
Piston Thrust Face O.D.²
New - CH18, CH20, CH22 (624 cc) ............................................... 76.967/76.985 mm (3.0302/3.0309 in.)
New - CH22/23 (674 cc)................................................................. 79.963/79.979 mm (3.1481/3.1488 in.)
New - CH25, CH26, CH730-745 .................................................... 82.986 mm (3.3194 in.)
Max. Wear Limit - CH18, CH20, CH22 (624 cc)............................. 76.840 mm (3.0252 in.)
Max. Wear Limit - CH22 (674 cc) ................................................... 79.831 mm (3.1430 in.)
Max. Wear Limit - CH25, CH26, CH730-745.................................. 82.841 mm (3.3136 in.)