Yanmar 3JH3E - 6. Camshaft and Tappets; 6-1 Camshaft

Chapter 2 Basic Engine
_6._C_'a_m_sh_a_fi_t_an_d_T_a.;.p.;;.p_e_ts
_______________________
3,4JH3(B)(C)E
6. Camshaft and Tappets
6-1 Camshaft
The
camshaft is normalized and the cam and bearing sur-
faces
are
surface hardened
and
ground. The
cams
have a
curve
that
minimized
the
repeated
shocks
on
the
valve
seats
and
maximizes valve seat life.
(1) Checking
the
camshaft side gap
The
load
is
received
by
the
standard bearing
near
the
end of the camshaft
by
the cam gear, resulting in rapid
wear
of the end of the bearing
and
enlargement
of
the
side gap.
Therefore,
measure
the thrust
gap
before
disassembly.
As
the
cam
gear
is shrink-fitted
to
the
cam,
be careful when replacing the thrust bearing.
Camshaft side gap
Printed
in
Japan
HINSHl-118009
Camshaft
gear
Thrust
metal
Side gap
Standard
0.05~0.25
mm
Wear limit
0.4
Push
rod
2-21
Camshaft bushing
Camshaft gear
Thrust
metal
(2}
Measure
the
camshaft height, and replace the cam
if
it
is
worn
beyond the
limit.
Camshaft height
lntakecam
Exhaust cam
Standard
.c
Cl>
·a;
::c
38.635~38. 765
mm
Wear limit
38.40