Cub Cadet 8454 Service Manual page 71

(C) Valve stem clearance
1. Remove the carbon from the valve guide.
2. Measure the valve stem O.D. with an outside
micrometer.
3. Measure the valve guide I.D. of cylinder head, and
calculate the clearance.
4. If the measurement exceeds the allowable limit,
replace the valve guide of the valve.
Valve stem Factory
clearance spec.
Allowable
limit
Valve guide
Factory
bore I.D.
spec.
Valve stem Factory
O.D. spec.
(D) Valve recessing
1. Clean the cylinder head, the valve face and the seat.
2. Insert the valve in the guide.
3. Measure the valve recessing with a depth gauge.
4. If the recessing exceeds the allowable limit, replace
the valve and check the valve seating.
Valve Factory
recessing spec.
Allowance
(E) Valve seat
1. Coat the valve face lightly with red lead and put the
valve on its seat to check the contact.
2. If the valve does not seat all the way around the
valve seat or the valve contact is less than 70%,
correct the valve seating as follows.
3. Apply compound on the valve face evenly.
4. Put the valve on its seat hold it with the valve flapper.
5. Turn and flap the valve back and forth on the valve
seat to lap.
6. Remove the compound and clean the valve and the
seat.
7. Apply oil on the valve face and finish to complete
fitting.
8. Repeat lapping until the valve seats correctly.
D569-W02 May-2003
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
0.040 ~ 0.070 mm
0.00157 ~ 0.00276 in.
0.1 mm
0.004 in.
8.015 ~ 8.030 mm
0.31555 ~ 0.31614 in.
7.960 ~ 7.975 mm
0.31339 ~ 0.31398 in.
0.2 ~ 0.5 mm
0.0078 ~ 0.0197 in.
0.8 mm
0.0315 in.
ENGINE
569W287A
569W288A
569W289A
2-49