GENERATOR EMI e’
INTAKE VALVE CLEARANCE .008”
EXHAUST . VALVE CLEARANCE .Oll”
FIGURE 9-13 -- VALVE DETAILS , VALVE - TAP?ET CLEARANCE
If bushings are grooved or worn beyond limits,
replace with Service type bushings which do not
have to be line reamed. Replace complete set of three. Rear and center bushings are identical--front
bushing is not interchangeable .with the others.
&ke sure oil holes line up after bushings are pressed
into crankcase. Camshaft to bushing running clearance must be .OOOS to .003?
VALVES - VALVE MECHANISM
Check valves, valve seats or inserts for signs of pitting, cracks or distortion. Also check condi-
tion of guides and clearance of valve stem to guides.
Use the following procedure:
Guide: To remove worn or damaged guide,
use rod with slightly smaller diameter and press guide down
In to chamber until it falls free of the crankcase.
Use Service guide for replacement. Service guides
have larger OD to allow for metal scraped from crankcase when old guide is removed.
Guides are
originally reamed to .306** - .
308” but must be re-reamed to .312” - .313” after they are installed in
crankcase.
Press guides to depth shown on accompanying valve detail drawings.
Valve and Valve Seats: Consult parts manual for correct valve numbers when replacing valves. Exhaust
valves are hard faced. Intake valve seats are machined into block and exhaust valves on hardened seat
inserts.
If valve seat insert is badly worn, warped, damaged or if seating surface is badly pitted, the
insert must be replaced. Inserts are a tight press fit in the crankcase. A commercial valve seat
removal tool is recommended for this job. Since removal causes loss of metal in the insert bore area,
use only Kohler service replacement inserts for proper retention.
Make sure service inserts are prop-
erly started and pressed evenly into bore to prevent cocking of the insert.
Seating surfaces should be held as close as possible to l/32’* width. Seats worn to more than
I/ 16” width must be reconditioned with 45’ and 15’ cutters to obtain proper width.
Reground or new
valves must be lapped in to provide proper fit.
Use a hand valve grinder with suction cup for final
lapping.
Lightly coat valve face with
‘*fine*’ grade of grinding compound then rotate valve on seat with
grinder. Continue grinding until smooth surface is obtained on seat and on valve face.
I
Valve Clearance: Valve clearance must be checked after resurfacing and lapping in. Install valves in
guides, rotate camshaft to position where cam has no effect on tappet.
Clearance (cold) is shown above
for intake and exhaust valves. Loosen adjusting screw,
turn in or out until proper clearance is attained.
To Next Page
Loading...
