Mercury 40 FourStroke - Inspection; Cylinder Bore

CYLINDER BLOCK/CRANKCASE
Page 4B-1790-857046R1 NOVEMBER 2001
Inspection
Cylinder Bore
MEASURING CYLINDER BORE
1. Measure the cylinder bore diameter at three locations in both X and Y axis.
2. If the cylinder bore is beyond the standard limits listed in the tables below, it will be nec-
essary to re-bore the cylinder to accept the oversize piston.
NOTE: Measure at three locations (L
1
, L
2
, and L
3
) in both X and Y axis (D
1-6
).
L
1
=0.8 in. (20 mm)
L
2
=1.6 in. (40 mm)
L
3
=2.4 in. (60 mm)
1. Inspect:
a. Water jacket for mineral deposits/corrosion, clean if necessary.
b. Inner surface for score marks, repair if necessary.
2. Measure bore diameter with a cylinder gauge, re-bore or replace if necessary.
55837
D
1,2
D
3,4
D
5,6
L
1
L
2
L
3
Cylinder Bore Specifications
Bore Size Maximum Taper/Out-of-Round
Standard Bore
2.5591 in. (65 mm)
0.003 in.(0.08 mm)
Oversize Bore-0.010 in. (0.25 mm)
2.5689 in. (65.25 mm)
0.003 in.(0.08 mm)
Oversize Bore-0.020 in. (0.50 mm)
2.5787 in. (65.5 mm)
0.003 in.(0.08 mm)
NOTE: Taper=(Maximum of D
1
or D
2
)–(Minimum of D
5
or D
6
)