Yanmar 4BY2, Руководство по обслуживанию, Страница: 121 / 248

ENGINE Cylinder Block and Crankshaft
12/05
BY Service Manual 5-59
© 2009 Yanmar Marine International
12. Measure bearing oil clearance to help
determine extent of wear. See Measure Oil
Clearance on page 5-59.
Note: Main bearing caps 1 to 5 are marked on
the exhaust side.
Note: All bearing caps must be installed in their
original locations.
Note: 6BY2 Engines: Main bearing caps No. 6
and 7 are not marked, but No. 6 is the
location of the thrust bearing
(Figure 5-108).
Figure 5-108
Figure 5-108
13. Remove the crankshaft bearing caps and main
bearing inserts (Figure 5-109).
Figure 5-109
Figure 5-109
14. Remove crankshaft. Inspect and measure
crankshaft journals as required.
Measure Oil Clearance
Oil clearance should be checked during
disassembly to determine the extent of wear, and
during reassembly to ensure long engine life. The
same procedure is done for both connecting rods
and main bearings.
1. Remove the bearing cap. Do not remove the
bearing inserts at this time.
2. Wipe oil from the bearing insert and crankshaft
journal surfaces.
3. Place a piece of PLASTIGAGE
®
(Figure 5-110, (1)) along the full width of the
bearing insert. NOTICE: NEVER rotate
crankshaft when using PLASTIGAGE. A false
reading may result.
Figure 5-110
Figure 5-110
4. Install the bearing cap using the old bolts and
tighten to specification. See Special Torque
Chart on page 5-8.
5. Remove the bearing cap.
0001 898
(1)