Cub Cadet MTD 90 Series - Manual (Page 107)

Cylinder head
101
Valves
The valves and valve seats can be serviced by grinding and lapping or the head can be replaced. Depending on
local machine and labor costs, it is probably more economical to replace the cylinder head versus servicing the
valves.
To service the valves:
NOTE: Servicing valves during the warranty period will
void the warranty. Warranty valve repairs are to be
accomplished by replacing the cylinder head.
1. Remove the cylinder head by following the steps
described earlier in this chapter.
2. Remove the rocker arms by:
2a. Remove the jam nuts.
2b. Remove the fulcrum nut.
2c. Slide the rocker arms off of the rocker studs.
3. Remove the valve retainers by applying light finger
pressure and moving the retainer so that the valve
stem passes through the large part of the “keyhole”
opening in the retainer. See Figure 9.10.
NOTE: The valve keepers are not interchangeable.
NOTE: The exhaust valve has a cap called an “adjuster”
on it. The cap needs to be pulled off before the
keeper can be removed. See Figure 9.11.
NOTE: If the engine has a dropped valve, remove the cyl-
inder head, inspect the valve and the piston for
damage.
Figure 9.10
Press down
and slide off
Figure 9.11
Secondary valve
keeper
Valve keeper