Honda C50 - Cylinder Disassembly; Camshaft Inspection; Cam Sprocket Teeth Base Contour; Cylinder Cross Section

20
Figure 3-36. Cc- ~ ·::"· · e·,;-:
Cam sprocke t
Figure 3- 37 . C om sp ro cket tee h bose conto ur
Figure 3-
38. Cy li nder
Cam chai n guide roll er
Cam chain guide
roll er pi n
Figure 3-
39 . Cyl inder cross sectio n
3. ENG IN~
a.
The inlet valve ope ns at 5° (top dead center f or
C50, C50M , C65, C65 Ml before top dead center of
the piston movement and closes at 30 ° 120 ° for C50,
C50M , C65, C65M l after botto m dead center,
per mitting an open duration of 2 15° (200° for C50 ,
C50M, C65, C65Ml. The exhaust valve opens at
40° 1 25° for C50 , C50M , C65 , C65Ml before bottom
de ad center a nd closes 5° ,!5° before top dead cent er
'or C50, C50M , C65, C65Ml after top dead center.
- his a llo ws 225° 1200° -" for C50 , C50M , C65 , C65M,l
~ ' exhaust valve ope n duration . This sequence
3- 35 and is called the valve timing
spec io n
R' ht
lg
en d
die.
Shaft
run out
Cam
height
L
eft end
bearing
die
Right end
bearing
die
(Fig. 3- 36)
:ond ord Value
29c;m 1 1.140in .l
- 0. 060 10. 00 20 in.)
- 0. 073 10. 0030 in .)
II
5. 076
10.2 00 in.)
29 mm 1 1.1 40 in .l
+0.02 1
10.0008
in.)
+o . oo 10 .000 in .>
II
I
Serv iceab le lim it ·
Rep lace if under
28 .8 I 1.135 in.t •
II
Replace if over
0. 05
10.0020 i n.)
Replace
if under
4.9
10.190 in.l
Replace if
over
29.06
11.145
in .)
"
121 Cam sprocket root diam eter
Stand ard value -> 53 . 41 ±0 .02 5 12 .104±0 .001 i n)
Se r viceab le limit -> Replace if und er 53.0 12 .09 in)
5. CYLINDER
The cylind er is made of special cast ir on . The
inside
cy linder wa ll is exposed to high ' t em p era tu re
and pressure t oge ther w ith the wearing action of the
reciprocating pist on ope ra ting at high speed to pr o- .
duce a
grea t wear i ng effect. Add ed to thi s, the dust
in t
he air and the fo reign object and the metallic
dust
co ntaminating the oil will hasten the rat e of
wear, the refor e, adequate a tt entio n should be given
to the cleaning of the air filter and the oil change.
A gasket
is installed be t ween the cyli nder and the
cylinder head
to maintain a seal. (Fig. 3- 37, 3- 38)
a. Disassembly
(1 l Re m ove the cy lind er h ead in accordance with
sec tion 3.21 a.
121 Remove the 6mm cylinder HS bolt s.