Yanmar 6LY3 series Service Manual page 91

Inspecting the Cylinder Block and Components
12/05
Measuring Cylinder Bores for
Out-of-Round:
Use a Dial Bore Gauge to measure the cylinder
bore diameters. Measure the cylinder bore twice at
right angles at positions 4 and 5 as shown in
Figure 5-13.
Record the following measurements:
1. Two measurements at position 1 at the top of
the cylinder bore.
2. Two measurements at position 2 in the middle
of the cylinder bore.
3. Two measurements at position 3 at the bottom
of the piston ring travel in the cylinder bore.
This produces six different measurement values.
Calculate the average value of all the
measurements for each cylinder bore and compare
with the wear limits. See Measuring Cylinder Bore
Diameters on page 5-25.
6LY3 Service Manual
Measuring Cylinder Bore Diameters
Measure the cylinder bore diameters and compare
the values with the wear limits stated below.
Cylinder Bore
Diameter
Cylinder Roundness
Cylindricity
© 2007 Yanmar Marine International
Cylinder Wear Limits
Item Standard
105.900-105.930 mm
(4.169-4.170 in.)
0.03 mm (0.001 in.)
or less
0.02 mm (0.0007 in.)
or less
ENGINE
Limit
105.950 mm
(4.171 in.)
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5-25