Yanmar 3JH4E Service Manual page 133

(3) Camshaft and bearing hole measurement
Measure the camshaft outside diameter with a
micrometer. The oil clearance shall be calculated by
subtracting the measured camshaft outside diameter
from the inside diameter of the camshaft bearing or
bushing. The camshaft bushing at gear case side is
measured with a cylinder gage after insertion to the
cylinder.
Replace if they exceed the limit or are damaged.
Place Item
Bushing I.D.
Camshaft
Gear side O.D.
Oil
clearance
Bushing I.D.
Camshaft
Intermediate
O.D.
position
Oil
clearance
Bushing I.D.
Camshaft
Flywheel
O.D.
side
Oil
clearance
(4) Bending of the camshaft
Support both ends of the camshaft with V-blocks, place
a dial gauge at the central bearing areas and measure
bending. Replace if excessive.
NOTE:
The reading on the dial gauge is divided by two to
obtain the camshaft bend.
Camshaft bend
Standard
44.990-45.055
44.925-44.950
0.040-0.130
45.000-45.025
44.910-44.935
0.065-0.115
45.000-45.025
44.925-44.950
0.050-0.100
Standard Limit
0.02 or less 0.05
5. Inspection and Servicing of Basic Engine Parts
mm
(Camshaft outside diameter)
Limit
45.130
44.890
0.240
45.100
44.875
0.225
45.100
44.890
0.210
mm
117
Flywheel side
Micrometer
Dial gage
V-block
(Camshaft bend)