Service and Repairs

16
Specifi cations
KohlerEngines.com 17 690 01 Rev. L
CLEARANCE SPECIFICATIONS
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CH245/CH255 CH260/CH270 CH395 CH440
Cylinder Bore
Bore I.D.
New
70.027/70.035 mm
(2.7570/2.7573 in.)
70.020/70.035 mm
(2.7570/2.7573 in.)
78.000/78.015 mm
(3.0709/3.0714 in.)
89.000/89.015 mm
(3.5039/3.5045 in.)
Max. Wear Limit 70.200 mm (2.764 in.) 78.185 mm
(3.0781 in.)
89.185 mm
(3.5112 in.)
Max. Out-of-Round
Max. Taper
12.7 microns (0.0005 in.)
12.7 microns (0.0005 in.)
Cylinder Head
Max. Out-of-Flatness 0.10 mm
(0.0039 in.)
0.08 mm
(0.003 in.)
0.1 mm (0.0039 in.)
Governor (Mechanical)
Governor Cross Shaft -to-
Crankcase Running Clearance
0.013/0.075 mm
(0.0005/0.0029 in.)
0.020/0.069 mm (0.0008/0.0027 in.)
Governor Cross Shaft O.D.
New
5.955/5.980 mm
(0.2344/0.2354 in.)
7.955/7.980 mm
(0.3132/0.3142 in.)
Max. Wear Limit 5.85 mm
(0.2303 in.)
5.942 mm
(0.2339 in.)
7.900 mm (0.3110 in.)
Governor Gear Shaft -to-Governor
Gear Running Clearance
0.09/0.19 mm
(0.0035/0.0074 in.)
0.022/0.134 mm (0.0009/0.0053 in.)
Governor Gear Shaft O.D.
New
Max. Wear Limit
6.028/6.043 mm
(0.2373/0.2379 in.)
6.018 mm
(0.2369 in.)
6.016/6.028 mm (0.2368/0.2373 in.)
6.003 mm (0.2363 in.)
Ignition
Spark Plug Gap 0.76 mm (0.030 in.)
Module Air Gap 0.254 mm (0.010 in.)
Piston, Piston Rings, and Piston Pin
Piston-to-Piston Pin Running
Clearance
0.009/0.016 mm (0.0003/0.0006 in.) 0.002/0.016 mm (0.0001/0.0006 in.)
Piston Pin Bore I.D.
New 18.004/18.005 mm
(0.7088/0.7090 in.)
18.000/18.008 mm
(0.7087/0.7090 in.)
20.000/20.008 mm
(0.7874/0.7877 in.)
Max. Wear Limit 18.05 mm (0.7106 in.) 20.05 mm
(0.7894 in.)
Piston Pin O.D.
New
17.992/17.995 mm
(0.7083/0.7084 in.) 17.992/17.998 mm (0.7083/0.7084 in.)
19.992/19.998 mm
(0.7871/0.7873 in.)
Max. Wear Limit 17.95 mm (0.7067 in.) 19.95 mm
(0.7854 in.)
Top and Center Compression Ring
Side Clearance
New Bore 0.04 mm (0.002 in.)
0.07 mm
(0.003 in.)
0.045 mm
(0.0018 in.)
Used Bore (Max.) 0.15 mm (0.006 in.) 0.11 mm
(0.004 in.)
0.10 mm
(0.004 in.)
Top Compression Ring End Gap
New Bore 0.325/0.400 mm (0.013/0.016 in.) 0.250/0.400 mm (0.010/0.016 in.)
Used Bore (Max.) 1.00 mm (0.039 in.)
Center Compression Ring End
Gap
New Bore
0.325/0.400 mm
(0.013/0.016 in.)
0.650/0.800 mm
(0.026/0.032 in.)
0.640/0.800 mm
(0.025/0.032 in.)
Used Bore (Max.) 1.00 mm (0.039 in.) 1.50 mm (0.059 in.)
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Values are in Metric units. Values in parentheses are English equivalents.