Cub Cadet Challenger 550, Service Manual

Page: 103 / 255

Engine
4‐7
Inspect the rocker arms
• Rocker arm lobes(1)
• Valve adjusters(2)
Look for discoloration, scratches or
pitting.
•
Rocker arms
•
Rocker arm shafts
Look for damage or
wear
Measure the inside diameter of the rocker
arm hole.
Out of spec limit 12.038mm
Check the surface of the rocker arm shafts
Look for worn, pitting or scratches.
Measure the outside diameter of the
rocker arm shaft with a micrometer.
Out of spec limit 11.96mm
Subtract the rocker arm shaft outer
diameter from the rocker arm inside
diameter to determine the clearance.
Clearance Limit 0.05mm
Inspect the Camshaft
•
Cam Lobes
(Look for discoloration, scratches
or pitting)
•
Camshaft Journal
Look for wear or damage.
Measure external diameter with a
micrometer. (Out of spec, replace)
Look at rotor “I” mark alignment.
Inspect the camshaft sprocket and chain for
wear and fitment.
Inspect the decompression system
•
Inspect while sprocket is still on the
camshaft.
Check that the decompression lever
pin (1) projects from the camshaft.
Check that the decompression cam
(1) moves smoothly.