John Deere stx38 - Manual (Page 68)

3 - 36
4/23/97
REPAIR ENGINE
LAP VALVES
IMPORTANT: Valves and seats should be lapped if
they do not make good contact.
1. Apply light coat of lapping compound to valve face,
then turn valve in seat using vacuum cup tool.
2. Check valve every 8 strokes until a uniform ring
appears around surface of valve face.
3. Wash parts in solvent to remove lapping
compound.
4. Check position of lap mark on face–lap mark must
be on or near center of valve face.
INSPECT BREATHER
1. Remove cap screw (A), plate (B), and reed (C).
2. Check that breather opening is clear.
3. Replace reed if it does not lie flat on casting.
4. Clean mating surface of any sealant residue (D).
REMOVE AND INSTALL FLYWHEEL
1. Remove blower housing sheet metal.
2. Remove four fan cap screws and washers (B) and
fan (A
3. Hold flywheel with strap wrench. Remove cap
screw (C).
4. Remove flywheel using a puller.
NOTE: Flywheel and magnets are not serviceable.
5. Inspect flywheel for cracks, chips, and broken teeth.
Replace as necessary.
6. Inspect for sheared or partially sheared key,
replace as necessary.
IMPORTANT: Check that crankshaft end and
flywheel hub are clean and free of lubricant, and
flywheel key is installed properly in keyway.
Improperly installed flywheel can cause
machine damage and serious personal injury.
7. Install flywheel and key on crankshaft.
8. Hold flywheel with strap wrench. Tighten cap screw
(A) to specification.
9. Check ignition module air gap (see Adjust Ignition
Module Air Gap, in the Tests and Adjustments
Group of the Electrical Section).
Specification:
Flywheel Cap Screw. . . . . . . . . . . . 68 N•m (50 lb-ft).
M52134
M55868
A
B
C
D
M52083
A
B
M52084
C
M52085