Mercury 40 Service Manual

4
B
CYLINDER BLOCK/CRANKCASE
Page 4B-190-828631R3 MARCH 1999
POWERHEAD
Section 4B - Cylinder Block/Crankcase
Table of Contents
Specifications 4B-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Tools 4B-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft 4B-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Block 4B-6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque Sequence 4B-8. . . . . . . . . . . . . . . . . . . . . . . . .
Powerhead Removal 4B-9. . . . . . . . . . . . . . . . . . . . . .
Removing Powerhead Components 4B-11. . . . . . . .
Cylinder Block Disassembly 4B-15. . . . . . . . . . . . . . .
Inspection 4B-18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Bore 4B-18. . . . . . . . . . . . . . . . . . . . . . . . .
Piston 4B-19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston Pin 4B-20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston Rings 4B-21. . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft 4B-22. . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Main Bearing Clearance 4B-22. . . . . . .
Checking Connecting Rod
Bearing Clearance 4B-24. . . . . . . . . . . . . . . . . . . . .
Thermostat 4B-26. . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Pressure Switch 4B-26. . . . . . . . . . . . . . . . . . . .
Cylinder Block Reassembly 4B-27. . . . . . . . . . . . . . . .
Selecting New Main Bearings 4B-27. . . . . . . . . . .
Main Bearing Installation 4B-28. . . . . . . . . . . . . . .
Selecting New Connecting Rod Bearings 4B-29.
Installing Connecting Rod Bearings 4B-29. . . . . .
Connecting Rod Installation 4B-30. . . . . . . . . . . . .
Piston Ring Installation 4B-30. . . . . . . . . . . . . . . . .
Piston Installation 4B-31. . . . . . . . . . . . . . . . . . . . .
Crankshaft Installation 4B-32. . . . . . . . . . . . . . . . .
Crankcase Cover Installation 4B-34. . . . . . . . . . . .
Exhaust Cover Installation 4B-35. . . . . . . . . . . . . .
Drive Gear Installation 4B-36. . . . . . . . . . . . . . . . .
Installing Powerhead Components 4B-37. . . . . . .
Powerhead Installation 4B-43. . . . . . . . . . . . . . . . . . . .
Specifications
CYLINDER BLOCK
Type
Displacement
Number of Cylinders
4 Stroke Cycle – Over Head Camshaft
57 cu. in. (935cc)
4
STROKE Length 2.953 in. (75 mm)
CYLINDER BORE
Diameter
Standard
Oversize-0.020 in. (0.050 mm)
Taper/Out of Round Maximum
Bore Type
2.4803 in. (63.0mm)
2.5003 in. (63.5 mm)
0.003 in. (0.08 mm)
Steel
PISTON
Piston Type
O.D. at Skirt
Standard
Oversize-0.020 in. (0.50mm)
Aluminum
2.4783-2.4789 in. (62.950-62.965 mm)
2.4983-2.4989 in. (63.450-63.465 mm)
PISTON
CLEARANCE
Piston to Cylinder Clearance 0.0014 - .0026 in. (0.035 - 0.065 mm)
RINGS
Ring End Gap (Installed)
Top
Middle
Bottom (Oil Ring)
Side Clearance:
Top
Middle
0.006 - 0.012 in. (0.15 - 0.03 mm)
0.012 - 0.020 in. (0.30 - 0.50 mm)
0.008 - 0.028 in. (0.20 - 0.70 mm)
0.002 - 0.003 in. (0.04 - 0.08 mm)
0.001 - 0.003 in. (0.03 - 0.08 mm)
COMPRESSION
RATIO
Compression Ratio
Cylinder Compression (cold
engine @ W.O.T.)
9.8:1
170 -190 lb./in
2
(Peak)
PISTON PIN Piston Pin Diameter 0.6285 - 0.6287 in. (15.965 - 15.970 mm)

Mercury 40 Specifications

General

Brand	Mercury
Model	40
Category	Outboard Motor
Language	English