Cub Cadet 8454 - Manual (Page 71)

ENGINE
2-49 D569-W02 May-2003
12
13
11
10
78
2
1
0
6
5
4
39
569W289A
569W288A
569W287A
Valve stem
clearance
Valve guide
bore I.D.
Valve stem
O.D.
(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.
(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.
Factory
spec.
Allowable
limit
Factory
spec.
Factory
spec.
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.
Valve
recessing Factory
spec.
Allowance
0.2 ~ 0.5 mm
0.0078 ~ 0.0197 in.
0.8 mm
0.0315 in.
(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.