3-9. CYLINDER HEAD ASSEMBLY AND SPACER PLATE - REPLACE/REPAIR (Cont'd)
(2) Check cylinder head for warpage
using a straightedge and feeler
gage. Replace a warped cylinder
Refer to page 2-29 for additional
cleaning instructions and warnings.
(3) Check cylinder head for cracks,
using liquid dye and/or magnetic
particle inspection methods.
(1) Thoroughly clean cylinder head
Replace a cracked cylinder head.
with an approved solvent or
other approved method of carbon
Carbon on the face of a valve
(2) Thoroughly clean both surfaces
indicates blow-by due to a faulty
of the spacer plate, using an
seat. Black carbon deposits,
approved cleaning method.
extending from the valve seats to
the valve guides may result from
(3) Clean carbon from the valve
cold operation due to light loads
stems and wash the valve with
or the use of too light a grade
of fuel. Rusty brown valve
heads, with carbon deposits
(4) Clean valve springs with an
forming narrow collars near the
approved solvent and dry
valve guides, is evidence of high
operating temperatures. High
operating temperatures are
normally due to overloads,
inadequate cooling, or improper
Be very careful when cleaning the
timing which results in
rotocoil o Do not disassemble
carbonization of the lubricating
rotocoil as it can be easily
damaged. Be sure to keep the
solvent clean as foreign material
(4) Inspect the valves stems for
entering the rotocoil will cause
scratches or scuff marks.
Inspect the valve faces for
(5) Use a clean, approved cleaning
ridges, cracks, or pitting. If
any of these defects occur,
solvent to clean the rotocoils
replace the valve.
and locks, and dry them
(5) If valves can be used again,
grind the valves and reinspect.
(6) Clean the inside diameter of the
Refer to Table for valve
valve guides with a brush and
approved cleaning solvent. Remove
if distortion is more than the
all gum and carbon deposits.
dimensions, given in Table 3-2.
(1) Visually inspect the cylinder
head and spacer plate for cracks,
heat deterioration, or other
damaqe. Replace a damaged
cylinder head and/or spacer plate.