824854T20 Mercury CARBURETOR, (WME 108-3)

Illustration 1 g02613840
Table 1
Specification for 341-3640 Piston and Rod Gp, and 371-0825 Piston    
Item     Qty     Part     Specification Description    
Prior to the installation of the piston rings, lubricate the ring grooves with clean engine oil. After assembly of the piston rings, lubricate the mating surfaces of the rings to the cylinder liner with clean engine oil.    
1     1     229-1632 Top Piston Ring     Install the top piston ring with the "UP-1" side toward the top of the piston.
Thickness of new top piston ring is
4.5 mm (0.18 inch).    
Clearance between the ends of the piston ring when the piston ring is installed in a cylinder liner bore of
170 mm (6.7 inch) is
0.625 0.125 mm (0.0246 0.0049 inch).
Increase in the clearance between the ends of the piston ring for each
0.03 mm (0.001 inch) increase in the cylinder liner bore is
0.08 mm (0.003 inch).
2     1     144-5695 Intermediate Piston Ring     Install the intermediate piston ring with the "UP-2" side toward the top of the piston.
Thickness of new intermediate piston ring is
3.785 mm (0.1490 inch).    
Clearance between the ends of the piston ring when the piston ring is installed in a cylinder liner bore of
170 mm (6.7 inch) is
1.00 0.15 mm (0.039 0.006 inch).
Increase in the clearance between the ends of the piston ring for each
0.03 mm (0.001 inch) increase in the cylinder liner bore is
0.08 mm (0.003 inch).
3     1     165-6668 Oil Control Piston Ring     Ends of the oil control piston ring should be a distance of 180 degrees from the ring end gap when the piston ring is assembled.
Width of groove in new piston for the oil control piston ring is
4.055 0.015 mm (0.1596 0.0006 inch).    
Thickness of new oil control piston ring is
3.980 0.010 mm (0.1567 0.0004 inch).
Clearance between the ends of the piston ring when the piston ring is installed in a cylinder liner bore of
170 mm (6.7 inch) is
0.65 0.15 mm (0.026 0.006 inch).
Increase in the clearance between the ends of the piston ring for each
0.03 mm (0.001 inch) increase in the cylinder liner bore is
0.08 mm (0.003 inch).
After all of the piston rings have been installed, rotate the piston rings so that the end gaps are separated by 120 degrees. The ring gap for the oil control piston ring must be aligned in the plane of the pin bore.
4     -     -     Diameter of the bore in the finished bearing that is installed into the piston skirt for the piston pin is
70.0705 0.0075 mm (2.75868 0.00030 inch).    
5     1     302-3451 Piston Pin     Before assembly of the piston pin, lubricate piston pin, piston pin bore, and connecting rod eye with clean engine oil.
Outside diameter is
69.930 0.005 mm (2.7531 0.0002 inch).
Length is
101.85 0.15 mm (4.010 0.006 inch).    
6     2     253-1238 Pin Retainer     Install the pin retainer with the gap toward the top of the piston.
Thickness of new pin retainer is
2.36 0.08 mm (0.093 0.003 inch).
Width of groove in new piston for the pin retainer is
2.75 0.1 mm (0.108 0.004inch).