Kohler CH18 Service Manual page 13

CLEARANCE SPECIFICATIONS
Piston, Piston Rings, and Piston Pin (Style B continued)
Middle Compression Ring End Gap
New Bore
Used Bore (Max)
Thrust Face O.D.
New
Max. Wear Limit
Piston Thrust Face-to-Cylinder Bore Running
Clearance
New
Valves and Valve Lifters
Hydraulic Valve Lifter to Crankcase Running Clearance
Intake Valve Stem-to-Valve Guide Running Clearance
Exhaust Valve Stem-to-Valve Guide Running Clearance
Intake Valve Guide I.D.
New
Max. Wear Limit
Exhaust Valve Guide I.D.
New
Max. Wear Limit
Valve Guide Reamer Size
Standard
0.25 mm O.S
Intake Valve Minimum Lift
Exhaust Valve Minimum Lift
Nominal Valve Seat Angle
Values are in Metric units. Values in parentheses are English equivalents.
4
CH620/CH640 engines changed from 624cc to 674cc; displacement can be confi rmed on engine nameplate.
8
Measure 6 mm (0.2362 in.) above bottom of piston skirt at right angles to piston pin.
9
Measure 13 mm (0.5118 in.) above bottom of piston skirt at right angles to piston pin.
10
24 690 06 Rev. P
CH18/CH20/
CH620/CH621/
CH640/CH641
4
KohlerEngines.com
CH22/CH23/
CH22/ CH620 /
8
CH640 /
8
CH670/CH680
1.400/
1.679 mm
(0.0551/
0.0661 in.)
1.941 mm
(0.0764 in.)
79.966 mm
(3.1483 in.)
10
79.821 mm
(3.1426 in.)
10
0.025/
0.068 mm
(0.0010/
0.0027 in.)
10
0.0241/0.0501 mm (0.0009/0.0020 in.)
0.038/0.076 mm (0.0015/0.0030 in.)
0.050/0.088 mm (0.0020/0.0035 in.)
7.038/7.058 mm (0.2771/0.2779 in.)
7.134 mm (0.2809 in.)
7.038/7.058 mm (0.2771/0.2779 in.)
7.159 mm (0.2819 in.)
7.048 mm (0.2775 in.)
7.298 mm (0.2873 in.)
8.07 mm (0.3177 in.)
8.07 mm (0.3177 in.)
45°
Specifi cations
CH25/
CH730/
CH740 CH750
1.519/1.797 mm
(0.0598/0.0708 in.)
2.051 mm (0.0808 in.)
82.978 mm (3.2668 in.)
9
82.833 mm (3.2611 in.) 9
0.019/0.062 mm
(0.0007/0.0024 in.)
9
13