Product Manual B

39
Disassembly/Inspection and Service
18 690 06 Rev. B KohlerEngines.com
Remove Valves
NOTE: Mark location of any part removed that will be
reused.
1. Supporting head of valve from below, depress valve
keeper and valve spring until keeper can be
released from valve stem. Remove valve spring and
valve from head. Repeat this procedure for
remaining valve.
2. Remove and replace intake valve stem seal
whenever cylinder head is serviced or disassembled.
Valve Details
D
D
D
B
C
A
E
Item Dimension Intake Exhaust
A
Head Diameter—Specifi cation
25 mm + 0.1 mm
(0.9842 in. + 0.0039 in.)
24 mm + 0.1 mm
(0.9449 in. + 0.0039 in.)
Head Diameter—Maximum 25.1 mm (0.9881 in.) 24.1 mm (0.9488 in.)
Head Diameter—Service Limit 24.9 mm (0.9803 in.) 23.9 mm (0.9409 in.)
B Stem Diameter—Specifi cation 5.5 mm (0.217 in.) 5.438 mm (0.214 in.)
Stem Diameter—Maximum 5.491 mm (0.216 in.) 5.430 mm (0.214 in.)
Stem Diameter—Service Limit 5.340 mm (0.210 in.) 5.280 mm (0.208 in.)
C
Valve Length—Specifi cation
64 mm + 0.15 mm
(2.5197in. + 0.0059 in.)
62 mm + 0.15 mm
(2.4409 in. + 0.0059 in.)
Valve Length—Maximum 64.15 mm (2.5256 in.) 62.15 mm (2.4468 in.)
Valve Length—Service Limit 64.15 mm (2.5256 in.) 62.15 mm (2.4468 in.)
D Face/Seat Width—Maximum 2.0 mm (0.079 in.) 2.0 mm (0.079 in.)
E Face/Seat Angle 90°-90.5°/89.5°-90° 90-90.5°/89.5°-90°
Stem to Guide—Specifi cation 0.024 mm (0.0009 in.) 0.098 mm (0.0038 in.)
Stem to Guide—Maximum 0.039 mm (0.0015 in.) 0.112 mm (0.0044 in.)
Stem to Guide—Service Limit 0.10 mm (0.0039 in.) 0.12 mm (0.0047 in.)
Stem to Guide Running Clearance—Specifi cation 0.020 mm (0.0008 in.) 0.030 mm (0.0008 in.)
Stem to Guide Running Clearance—Maximum 0.044 mm (0.0017 in.) 0.054 mm (0.0021 in.)
Stem to Guide Running Clearance—Service Limit 0.10 mm (0.0039 in.) 0.12 mm (0.0047 in.)
Valve Guide – Specifi cation 5.5 mm (0.2165 in.) 5.5 mm (0.2165 in.)
Valve Guide – Maximum 5.512 mm (0.2170 in.) 5.512 mm (0.2170 in.)
Inspection and Service
After cleaning, check fl atness of cylinder head and
corresponding top surface of crankcase, using a surface
plate or piece of glass and feeler gauge. Maximum
allowable out of fl atness is 0.1 mm (0.0039 in.).
Carefully inspect valve mechanism parts. Inspect valve
springs and related hardware for excessive wear or
distortion. Check valves and valve seats for evidence
of deep pitting, cracks, or distortion. Check running
clearance between valve stems and guides.