Inspect Crankshaft - Yanmar BY Series Service Manual

Cylinder Block and Crankshaft
12/05

Inspect Crankshaft

1. Use the color check method or MAGNAFLUX
to inspect the crankshaft for cracks. Replace
the crankshaft if evidence of fractures are
found.
2. Measure the outside diameter of each crankpin
and main bearing journal. Take measurements
at several places around each bearing surface.
If not within specification, grind the journals and
install undersize bearings, or replace the
crankshaft.
Crankshaft Specifications
Main Bearing
Journals
Standard Yellow
Standard Green
Standard White
Undersize 1 (U 0.25)
Yellow
Undersize 1 (U 0.25)
Green
Undersize 1 (U 0.25)
White
Undersize 2 (U 0.50)
Yellow
Undersize 2 (U 0.50)
Green
Undersize 2 (U 0.50)
White
Crankshaft Bearing
Clearance, Radial
Connecting Rod
Journals
Standard
Size 1
Size 2
Radial Bearing Play
BY Service Manual
Specification
59.977 to 59.983 mm
(2.3613 to 2.3615 in.)
59.970 to 59.976 mm
(2.3610 to 2.3613 in.)
59.964 to 59.969 mm
(2.3608 to 2.3610 in.)
59.727 to 59.733 mm
(2.3514 to 2.3517 in.)
59.720 to 59.726 mm
(2.3512 to 2.3514 in.)
59.714 to 59.719 mm
(2.3509 to 2.3511 in.)
59.477 to 59.483 mm
(2.3416 to 2.3418 in.)
59.470 to 59.476 mm
(2.3413 to 2.3416 in.)
59.464 to 59.469 mm
(2.3411 to 2.3413 in.)
0.019 to 0.052 mm
(0.0007 to 0.0020 in.)
Specification
45.00 -0.009 / -0.025 mm
(1.7716 -0.0004 / -0.0010 in.)
44.75 -0.009 / -0.025 mm
(1.7618 -0.0004 / -0.0010 in.)
44.50 -0.009 / -0.025 mm
(1.7520 -0.0004 / -0.0010 in.)
0.015 - 0.050 mm
(0.0006 - 0.0020 in.)
© 2009 Yanmar Marine International
Thrust Bearing
®
Standard
Size 1
Size 2
Crankshaft End Play
ENGINE
Specification
25.00 +0.020 / +0.066 mm
(0.9842 +0.0008 / +0.0026 in.)
25.2 +0.020 / +0.066 mm
(0.9921 +0.0008 / +0.0026 in.)
25.4 +0.020 / +0.066 mm
(1.000 +0.0008 / +0.0026 in.)
0.06 to 0.25 mm
(0.0024 to 0.0098 in.)
5-61