To
instail the replacement sl
.....
oil its bore and
the
crankshaft gear. using clean. fresh engine o
il
;
ho
ld
the
s
leeve
sq
uarely
and
drive
it into
it
s
posj-
tion,
keeping
it
trued
up
a
ccu
rately
.
(8) Inspection
of
cr.lIlkshaft keyway and screw threads
The forward end
of
the crankshaft
is
thr
eaded and
has
a
ke
yway. V
is
ually examine
th
e
thr.ad
s
and
keyway
and.
as
necessar
y.
repair
them
.
Pistons
and
piston
rings
(I)
Piston inspection
lospe
Cl
each
pist
on
for
any
abn
o
rmal
wear
of
its
sliding su
rf
ace, for cracks
at
the crown and
for
evidence
of
me
lt
in
g
or
fusion. Examine the
ring
gr
oo
ve
s
for
stepped
wear
ilnd
sl
oped
w
ear.
Rep
lace
pistons found
in
bad condition.
(2) Piston clearance in the bore
Mik
e each piston at the positions listed
be
low; and
by
re
fe
rring
to
the
bor
e diameter.
previou
sly
determ
in
ed,
of
its
s.lee
ve
, compute the r
adlal
Unit:
mm
{in.)
Item
Sta
ndard
Serv
i
ce
limit
Standard size
93
.
86±0.0IS
(3.69
53
±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
)
ski
rt)
oversI
ze
O.
SO-mm
94.36: 0.015
(0
.0197 in.)
(3.
71
50
:0.00059)
oversize
At
piston
0.615-0.680
c
rOwn
(0.02421-0.02677)
At
No.! land
0.465-0530
(0.0183
1-0
.02087)
At
No.2 l
and
0.4
1
5-0
.480
Piston
(0.01634-il.
01890)
dear-
Just below
0.27
5-il.340
02
ance
oil ring
(0.01 083-{).0 1339)
(0.008)
in
!7mm
bo
re
(0.669 in.)
0.
195-0
.2
60
below oil
(0.00768-0.01024)
ring
37.5 mm
(1.476
",.)
0.1 55-{).220
below oil
(0
.00610
-0
.00
866)
ring
At skirt
0
.1
25
-o.!90
(O.00492-{).OO748)
~
MAINTENANCE AND ADJUSTMENT
d
ea
rance at each position.
if
the
pi
ston 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
pi
ston
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
diff
er
by
plus or m
inu
s
3 grams
(O
.! oo) from the
we
ight indicated on
the crown.
If any of the pistons has
to
be
rep
laced
by
an
oversil.e p
is
ton, replace
the
other
three
l
too,
by
th
ose
of
the
sa
me
overs.
ize
_
(3)
Piston ring
gap
Be sure that each piston ring has its gap within the
serVice
limit.
Measure
the
rin
g
gap
with a
thlc
kn
e
ss
g
auge
,
holding
the
ring
fitt
ed
in
a
new
sleeve.
57
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