Product Manual

Connecting Rod
Crankshaft pin journal diameter
29.000–29.013 mm
(1.1417–1.1422 in.)
Crankshaft pin journal diameter (service limit) 28.038 mm (1.1432 in.)
Piston pin bore diameter
16.010–16.021 mm
(0.6303–0.6307 in.)
Piston pin bore diameter (service limit) 16.025 mm (0.6309 in.)
Crankshaft
Crankshaft Runout
1.
Thoroughly clean the crankshaft and inspect the bearing surfaces. Replace the crankshaft if the bearing surfaces are
pitted, scored, or discolored.
2. Measure the crankshaft for runout. Replace the crankshaft if out of specification.
3138
Crankshaft
Runout 0.030 mm (0.00118 in.)
Crankshaft Bearing Journals
1.
Measure the crankpin journals.
2. Measure the crankshaft main bearing journals.
3. Replace the crankshaft if journals are out of specification.
a - Crankshaft pin journals
b - Main bearing journals
Crankshaft Bearing Journal
Crankshaft pin journal 28.972–28.985 mm (1.1406–1.1411 in.)
Crankshaft pin journal (service limit) 28.970 mm (1.1405 in.)
Main bearing journal 33.992 mm (1.3382 in.)
Main bearing journal (service limit) 33.972 mm (1.3374 in.)
Crankcase Main Bearings
Measure the crankshaft main bearing clearance as outlined in the following procedure. Replace the upper and lower bearings
as a set if out of specification.
Main Bearing Oil Clearance
Main bearing clearance 0.012–0.044 mm (0.0005–0.0017 in.)
Service limit 0.06 mm (0.002 in.)
Crankshaft Main Bearing Clearance Measurement
IMPORTANT:
Use new main bearings, do not reuse the removed main bearings.
1. Ensure that the mating surfaces on the crankcase cover and cylinder block are clear of debris.
2. Clean all the oil from the following areas:
a
b
3149
Cylinder Block/Crankcase
Page 4A-20 © 2018 Mercury Marine 90-8M0125265 eng NOVEMBER 2017