Yanmar 3YM30, Sevice Manual

Page: 144 / 224

5. Inspection and servicing of basic engine parts
129
(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.
(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.
mm
Item Standard Limit
Gear side Bushing I.D. 40.000-40.075 40.150
Camshaft
O.D.
39.940-39.960 39.905
Oil
clearance
0.040-0.135 0.245
Intermediate
position Bushing I.D. 40.000-40.025 40.100
Camshaft
O.D.
39.910-39.935 39.875
Oil
clearance
0.065-0.115 0.225
Flywheel
side Bushing I.D. 40.000-40.025 40.100
Camshaft
O.D.
39.940-39.960 39.905
Oil
clearance
0.040-0.085 0.195
mm
Standard Limit
Camshaft bend 0.02 or less 0.05
Flywheel side
Micrometer
(Camshaft outside diameter)
(Camshaft bend)
Dial gage
V-block