TM 10-4320-318-14
6-6. MAINTENANCE OF CYLINDER HEAD - (Cont)
b.
DISASSEMBLE<
(1) Disassemble rocker arm assembly as follows:
(a) Remove rocker arms (26) from rocker shaft (13).
(b) Loosen nuts (25).
(c) Remove adjusting screws (23), clamp (24), and nuts (25).
(2) Disassemble decompression lever (30) as follows:
(a) Remove pin (27) and remove pinion (28) from shaft (29).
(b) Remove decompression lever (30) with shaft (29).
(c) Remove pin (31) and decompression lever (30) from shaft (29).
(d) Remove O-ring (32).
(3) Disassemble oil priming device (35) as follows:
(a) Remove cap (33) with O-rings (34).
(b) Remove oil priming device (35) with O-ring (36).
(4) Using valve spring compressor, remove valves (43) and valve springs (37) as follows:
(a) Compress valve spring (37) and remove collets (38).
(b) Slowly release valve spring (37) and remove valve spring compressor.
(c) Remove cup (39), valve spring (37), cap (40), washer (41), seal (42), and valve (43).
c.
INSPECT.
(1) Clean and inspect cylinder head. If cylinder head is cracked or damaged, replace complete cylinder
head.
(2) Check contact surface for roughness. Machine contact surface up to a maximum of 0.0196 inch (0.45
mm).
(3) Measure valve guide bore diameter. If measurement exceeds 0.2756-0.2760 inch (10.0-10.011 mm),
replace valve guide.
(4) Inspect valve seats for pitting and looseness. Reface valve seats if pitted. Replace cylinder head if valve
seats are so worn that recutting is no longer possible.
(5) Inspect contact surface for cylinder head cover. Replace cylinder head if surface is rough or damaged.
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