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To
instail
the
replacement sl ..... oil
its bore
and
the crankshaft
gear.
using clean
.
fresh engine
oil
;
hold
the
sleeve
squarely and
drive
it
into
its
posj-
tion,
keeping it trued
up
accurately
.
(8) Inspection of cr.lIlkshaft keyway and
screw threads
The forward end of
the
crankshaft
is
threaded and
has a
keyway.
Visually ex
amine
th
e
thr.ads
and
keyway
and. as
necessary
.
repair
them
.
Pistons
and
piston rings
(I) Piston
inspection
lospe
Cl
each
piston
for any abn ormal wear of its
sliding
surface
,
for
cracks
at
the crown and
for
evidence
of melt
in
g
or
fusion. Examine
the
ring
grooves
for
stepped
wear ilnd sloped
wear.
Replace
pistons found in bad condition.
(2)
Piston
clearance in the bore
Mike
each piston
at
the
positions listed
be
low;
and
by re ferring
to
the
bore
diameter.
previously
determined
,
of
its
s.leeve
,
compute
the
radlal
Un
it: mm {in.)
Item
Standard
Service
limit
Standard
size
93 .86±0.0IS
(3.6953
±0.00059)
Piston
0.2S-mm
diame·
94.11±0.015
-
0.2
tor (at
(0.0098 in.)
(3
.705
1=
0.(0059)
(-0.008
)
skirt)
oversIze
O.SO-mm
94.36:
0.015
(0.0197
in.)
(3.71
50
:0.00059)
oversize
At
piston
0.615-0.680
crOwn
(0.02421-0.02677)
At No.!
land
0.465-0530
(0.0183
1-0.02087)
At
No.2
land
0.4 15-0 .480
Piston
(0.01634-il.0
1890)
d
ear-
Just
below
0.275-il.340
02
ance
oil ring
(0.01 083-{)
.0
1339)
(0.008)
in
!7mm
bore
(0.669 in.)
0.195-0.260
below oil
(0.00768-0.01024)
ring
37 .5
mm
(1.476 ",.)
0.1
55-{).220
below
oil
(0.00610-0.00866)
ring
At skirt
0
.1
25-o.!90
(O.00492-{).OO748)
~
MAINTENANCE
AND ADJUSTMENT
d
ea
rance at
each
position.
if
the piston is
wom
down so much
as to
exceed
the timit
[-
0.2
rom
(-0.0079 in .)J at any
of
the,.
positions. replace
it.
--------
"'
ntlU
Miking
piston
Front
of
engine
t
pj~ton
weigl'll
Amount
of
offs!![
Pis10n
weight
marking and
pin
holo offset
[NOTE]
Before reassembling the eng;ne,
make
sure that
the
four
pistons
do no
t
differ
by
plus
or
minus
3 grams
(O.! oo)
from
the we ight indicated
on
the crown.
I
f
any
of
the
pistons has
to be
replaced
by
an
oversil.e
pis
ton
,
replace
the
other
three
l
too,
by
those
of
the
same
overs.ize
_
(3)
Piston ring
gap
Be sure that
each
piston ring has
its
gap
within
the
serVice
limit. Measure the
ring
gap with
a
thlckness
gauge,
holding
the ring
fitted
in
a new
sleeve.
57
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