Mercury 40 FourStroke User Manual

CYLINDER BLOCK/CRANKCASE
Page 4B-2 90-857046R1 NOVEMBER 2001
Specifications
CYLINDER
BLOCK
Type
Displacement
Number of Cylinders
4 Stroke Cycle – Over Head Camshaft
45.6 cu. in. (747 cc)
3
STROKE Length 2.953 in. (75 mm)
CYLINDER
BORE
Diameter
Standard
Oversize-0.010 in. (0.25 mm)
Oversize-0.020 in. (0.50 mm)
Taper/Out of Round Maximum
Bore Type
2.5591 in. (65 mm)
2.5689 in. (65.25 mm)
2.5787 in. (65.5 mm)
0.003 in. (0.08 mm)
Cast Iron
PISTON
Piston Type
O.D. at Skirt
Standard
Oversize-0.010 in. (0.25 mm)
Oversize-0.020 in. (0.50 mm)
Aluminum
2.5570 - 2.5578 in. (64.950 - 64.965 mm)
2.5669 - 2.5675 in. (65.2 - 65.215 mm)
2.5768 - 2.5774 in. (65.450 - 65.465 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)
0.0008 - 0.0024 in. (0.02 - 0.06 mm)
0.0008 - 0.0024 in. (0.02 - 0.06 mm)
COMPRESSION
RATIO
Compression Ratio
Cylinder Compression*
(Electric Models Only, Cold Engine @
W.O.T.)
9.8:1
180 - 210 psi (Peak)
PISTON PIN Piston Pin Diameter 0.6285 - 0.6287 in. (15.965 - 15.970 mm)
CONNECTING
ROD
Oil Clearance (Big End)
Small End Inside Diameter
0.0008 - 0.0020 in. (0.020 - 0.052 mm)
0.6293 - 0.6298 in. (15.985 - 15.998 mm)
CRANKSHAFT
Main Bearing Clearance
Crankshaft Run-out
0.0005 - 0.0017 in. (0.012 - 0.044 mm)
0.0018 in. (0.046 mm)

Mercury 40 FourStroke Specifications

General

Brand	Mercury
Model	40 FourStroke
Category	Outboard Motor
Language	English