Kohler Command PRO CS, Service Manual

Page: 119 / 162

10.7
Section 10
Internal Components
10
Hard starting, or loss of power accompanied by high fuel consumption may be symptoms of faulty valves.
Although these symptoms could also be attributed to worn rings, remove and check the valves first. After
removal, clean the valve heads, faces, and stems with a power wire brush. Then, carefully inspect each valve for
defects such as warped head, excessive corrosion, or worn stem end. Replace valves found to be in bad condition.
A normal valve and valves in bad condition are shown in the accompanying illustrations.
Normal: Even after long hours of operation a valve
can be reconditioned and reused if the face and
margin are in good shape. If a valve is worn to where
the margin is less than 1/32 in. do not reuse it. The
valve shown was in operation for almost 1000 hours
under controlled test conditions.
Bad Condition: The valve depicted here should be
replaced. Note the warped head; margin damaged and
too narrow. These conditions could be attributed to
excessive hours or a combination of poor operating
conditions.
Dimension
Head Diameter
Stem Diameter
Length
Face/Seat Width
Face/Seat Limit
Face/Seat Angle (Insert Area)
Valve Stem Bend Limit
Valve Guide
Guide Inside Diameter
Stem to Guide Clearance
Valve Clearance
Valve Seat Contact Width
Std.
Limit
A
B
C
D
E
Exhaust
27.0 mm (1.06 in.)
5.940/5.955 mm
(0.2339/0.2344 in.)
87.9 mm (3.46 in.)
0.7/0.9 mm (0.0276/0.0354 in.)
1.4 mm (0.055 in.)
90°
0.01 mm (0.0004 in.)
6.0/6.012 mm (0.2362/0.2367 in.)
0.045/0.072 mm
(0.00177/0.00283 in.)
0.1 mm (0.004 in.)
0.7 mm (0.03 in.)
1.7 mm (0.067 in.)
Intake
32.0 mm (1.26 in.)
5.948/5.963 mm
(0.2342/0.2348 in.)
88.1 mm (3.47 in.)
0.7/0.9 mm (0.0276/0.0354 in.)
1.4 mm (0.055 in.)
90°
0.01 mm (0.0004 in.)
6.0/6.012 mm (0.2362/0.2367 in.)
0.037/0.064 mm
(0.00146/0.00252 in.)
0.1 mm (0.004 in.)
0.7 mm (0.03 in.)
1.7 mm (0.067 in.)
CS8.5, CS10, CS12 Valve Specifications