MASSEY FERGUSON MF 14 - Page 76

MASSEY.FERGUSON
TECUMSEH
EA'G'A'ES
MODEL
H7O
GROUP
O-SECTION
V-PART 8
ll.
Check
cylinder head
for
cracks,
broken
cooling
fins,
or other
damage.
Lay
cylinder
head on
a flat
surface to
check for distortion or
warping. Replace
damaged
cylinder head.
12.
Check
valve
guides
for
scoring
and
wear. If
guides
are
worn to
more
than standard
guide sizes
listed in
"Specifications",
valve
guides
can
be
rebored
to
accommodate
a valve
with
a
t
/n-inch
oversized
stem.
Refer to
"Reboring
Valve Guides".
NOTE:
Vahse
guides
are permanentlg installed
in cglinder
and are not
replaceable.
13. To reassemble
engine,
proceed
as
follows:
a. Install
crankshaft, camshaft,
piston
and
rod as-
sembly.
b. Install
cylinder cover, valves and
breather
as-
sembly.
c. Install
magneto and cylinder
head. Tighten
head
bolts in
the sequence
illustrated
in
Fig.
9.
(Tighten
bolts to
torque indicated
in
"Specifications".
REBORING
THE CYLINDER
If
cylinder
is more than .005 inch larger than standard
bore size listed
in
"specifications,"
it
must be
rebored
as
follows:
I. Dismantle
engine as described
in
Steps
I through
5 of
"Cylinder."
2.
Thoroughly
clean cylinder with solvent.
3. Determine
if
cylinder should be rebored for .010
inch
or
.02,0 inch
oversize
piston
and
rings.
This
is the
nearest
available size which
will permit
clean-up
of
cylinder wear completely.
4. Use any
standard
commercial hone of suitable
size. Chuck hone
in
drill
press
that has a spindle speed
of
approximately
600 rpm.
5. Install
set
of coarse stones in hone and center
cylinder
under spindle
of drill
press.
Lower
hone to
point where lower
end of stones are
in
contact
with
Iowest point in
cylinder bore.
6. Rotate adjusting nut so that stones touch cylinder
wall
and
begin
honing at bottom of cylinder. Move hone
up and
down
at
rate
of 50 strokes
per
minute to avoid
cutting ridges in
cylinder wall. Every fourth of
fifth
stroke, move hone far enough to
extend
the stones one
inch
beyond
top
and bottom
ofcylinder
bore.
7.
Check
bore every thirty
or
forty
strokes
for size
and straightness to
make certain
that cutting
is pro-
gressing
satisfactorily.
If stones are collecting metal,
clean with a wire brush
each time hone is
removed.
B. Continue
honing
operation with coarse stones
until
cylinder bore is within .002 inch
of
desired finish
size.
Then
replace
coarse stones with
burnishing
stones
and
continue
in
same
manner until bore
is to rvithin
.0005
inch of desired
size.
9. Remove burnishing
stones and install finishing
stones
to
polish
cylinder to final
size.
10.
Clean cylinder with solvent
and
dry thoroughly.
Il.
When
reassembling
the
engine
(described
in
paragraph 13
of
"Cylinder"),
replace piston
and
piston
rings
with oversized parts.
i.
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Fis.
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