International Harvester Company Cub Lo-Boy C-60 Service Manual page 23

grooves in the stem to see that they have
not lost the shoulders through wear, which
prevents the valve seat retainer keys from
fitting snugly.
2. Inspect each valve. See that the
stem is not worn excessively and that the
head is not burned or warped. Check the
3. All valves having bent, worn, warped
or seriously pitted stems should be re-
placed. Replace any valve that cannot be
satisfactorily refaced with a definite mar-
gin maintained. The amount of grinding
necessary to true the valve face is a def-
inite indication of the valve head warpage'
from the axis or centerline of its stem.
With excessive warpage, a knife edge will be
ground on part or all of the valve head due
to the considerable amount of metal that
must be removed to completely reface.
Maximum heaviness in a valve head is re-
quired for strength and to provide as large
an area as pos sible for heat dissipation.
Knife edge valves lead to breakage and
warpage.
WRONG
WRONG
FEA-64460
CORRECT
4. Clean and examine all valve springs
for rust, pitting, broken or set coils. Test
each spring against the spring specifica-
tions (see "Specifications I') using a spring
load tester. Replace all springs that do not
meet specifications.
5. Clean all valve spring seats with
solvent, and examine them for rust, cracks
and bending characteristics. Replace parts
as necessary.
Valve Seat Retainer Keys
Clean parts thoroughly in solvent. Check
the ribs in the inside of the keys to see that
none are worn sufficiently to cause loose-
ness. The keys must fit snugly into the
valve stem groove. Check the keys for
wear on the outside surface which might
allow the valve spring retainer to slide
over the key.
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