TM 5-4310-227-15
c. Cleaning, Inspection, Testing and Repair.
is 16 ounces.
Refer to paragraph 4-22 (c) for cleaning, in-
spection, testing, and repair. The proper mini-
mum brush spring tension for 24-volt generator
assemble the generator.
ENGINE VALVES, VALVE GUIDES, AND SEAT INSERTS
Section VI.
4-24. General
valve are stellitetype valves; each is
The valve system of this engine consists of
equipped with a valve rotator. Be sum to
one intake and one exhaust valve. Both valves
identify the valves as they are removed,
because each valve must be reinstalled in
are spring-loaded and equipped with rotators
the same valve guide from which it was
to lessen the frequency of valve repair. The
removed.
valves are accessible by removing the cylinder
b. Cleaning, Inspection, and Repair.
head and valve chamber cover. Both valves op-
(1) Scrape and/or wire brush carbon from
erate in valve guides pressed into the engine
the head and stem of the valves and
block. The valves and valve seat inserts are
from the inside of the installed valve
made of stellite resist burning. The function of
guides.
the intake valve is to admit the fuel air mixture
(2) Remove varnish from the valve stems.
to the combustion chamber while the exhaust
Carefully clean all carbon from the in-
valve. controls the release of the exhaust gases
stalled valve seat inserts (2) with a
from the combustion chamber. Refer to TM 5-
fine wire brush.
2 8 0 5 - 2 0 3 - 1 4 for data applicable to model
(3) Inspect the valves for evidence of im-
OEG-458-ENG-3.
perfect seating, warpage, burning, or
wear and also inspect the valve face
for pits and grooves. Inspect the ends
Seat Inserts
of the valve stems for grooves or
a. Removal.
sco9res. Reface slightly worn or dam-
(1) Remove the cylinder head (para 3-
aged valves (f below).
(4) A f t e r cleaning with an approved
(2) Remove the valve chamber access cov-
cleaning solvent, inspect the valve
er (para 3-69).
springs, retainer locks, and valve ro-
(3) Using a valve spring compressor tool,
tators for wear or signs of metal fail-
compress the valve spring (22, fig. 4-
ure. Inspect the compression springs
for pressure and squareness. See that
ed and located; then remove the two
the valve rotators turn freely.
spring retainer locks (20) from the
(5) Inspect the valve stem clearance of
recess in the stem of the valve (1).
e a c h valve in its respective valve
(4) Remove the spring compressor tool
guide. If the valve stem-to-guide clear-
and lift the valve (1) out through the
ance is excessive, either the valve
top of the cylinder and crankcase as-
stem or the valve guide is worn. Re-
sembly (4).
place a valve guide having an inside
(5) Remove the valve rotator (21) and
diameter which measures in excess of
0.3130 inch (c below). Maximum al-
valve spring (22) from the valve
chamber.
lowable wear for the valves and valve
guides is 0.002 inch.
(6) Remove the other valve and related
(6) M e a s u r e the valve stem diameter.
components in a manner similar to
They should be replaced if the stem
t h a t described in (3) through (5)
diameter is less than 0.3080 inch.
above.
