
IMPORTANT: Do not measure inside diameter close to the connecting rod and bearing split line.
a -
Inside dial indicator
b -
Assembled rod and bearings
c -
Split line
6. Record the measurements.
7. Wipe the crankshaft connecting rod journal with a clean cloth. Remove any oil film.
8. Measure the crankshaft connecting rod journal diameter with a micrometer. Take a second measurement at a position on
the connecting rod journal at a point 90° from the first measurement.
a -
Measurement point "a"
b -
Measurement point "b"
Description
6.2 Liter (377 cid)
Diameter
53.3095–53.3295 mm (2.0988–2.0995 in.)
Taper
Production
0.005 mm (0.0002 in.) maximum
Out of round
Production
0.008 mm (0.0003 in.) maximum
NOTICE
Inadequate clearance or interference between the bearing and its mating surface will result in rapid bearing wear and
catastrophic component failure. Check all bearing clearances.
9. If the crankshaft rod bearing journal diameters are not within specifications, replace or recondition the crankshaft.
10. If the crankshaft rod bearing journal diameters are within specifications, determine bearing clearance by subtracting the
crankshaft connecting rod journal outer diameter from the inner diameter of the bearing from step 5.
Description
6.2 Liter (377 cid)
Clearance
Production
0.047–0.110 mm (0.0019–0.0043 in.)
11. If the clearance exceeds specifications, select a new, correct size bearing, and recheck the bearing clearance.
Connecting Rod Bearing Clearance, Plastigauge Method
The plastic gauge method is an optional method of determining connecting rod bearing clearance. Micrometer measurement is
the preferred method.
1. Wipe both upper and lower bearings and the crankshaft connecting rod journal with a clean soft cloth. Remove any oil film.
2. Install the bearings in the connecting rod and cap.
IMPORTANT: To obtain accurate measurements the connecting rod and upper bearing must be seated against the
connecting rod journal before installing the lower bearing and rod cap.
3. Rotate the crankshaft or move the connecting rod until the upper bearing is fully seated against the connecting rod journal
being measured.
a
b
c
30340
a
a
b
b
30347
Engine Inspection and Assembly
Page 3B-30
© 2016 Mercury Marine
90-8M0099748 eng DECEMBER 2015
Summary of Contents for MERCRUISER
Page 2: ......
Page 6: ...90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page iv...
Page 12: ...General Information Notes Page 1A 6 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 70: ...Maintenance Notes Page 1C 54 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 96: ...Troubleshooting Notes Page 1D 26 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 156: ...Installation Notes Page 2B 52 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 202: ...Engine Disassembly Notes Page 3A 46 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 286: ...Engine Troubleshooting Notes Page 3C 14 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 314: ...Waste Spark System Notes Page 4B 8 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 330: ...Charging System Notes Page 4C 16 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 404: ...MPI ECT Fuel System Notes Page 5A 34 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 424: ...All Models Notes Page 6A 20 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 448: ...Models with Closed Cooling Notes Page 6C 20 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 462: ...Water Flow Diagrams Notes Page 6D 14 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 474: ...Important Information Notes Page 7A 12 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 477: ...Manifolds and Elbows Notes 90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page 7B 3...
Page 538: ...Compact Hydraulic Steering Notes Page 8B 12 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 558: ...Notes Color Diagrams Page 10A 2 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 559: ...Notes Color Diagrams 90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page 10A 3...
Page 565: ......