30430A12 Mercury CHECK VALVE KIT

Illustration 1 g01273637
This piston has a square top ring. Use the 246-1176 Piston Ring Groove Gauge Gp for measuring the top ring groove.This piston has a Keystone type of intermediate ring. Use the 1U-6431 Piston Ring Groove Gauge Gp for measuring the intermediate ring groove. Refer to the instruction card that is with the gauge group.Note: Prior to the installation of the rings, the ring grooves must be completely lubricated with clean engine oil. After assembly, the mating surfaces of the rings to the cylinder liner must be completely lubricated with clean engine oil. (1) Top ringInstall the top ring with the "Up-1" side toward the top of the piston.When the piston ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 0.625 0.125 mm (0.025 0.005 inch) (2) Intermediate ringInstall the intermediate ring with the "Up-2" side toward the top of the piston.When the piston is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 1.00 0.15 mm (0.04 0.006 inch) (3) Oil control ringWidth of groove in piston for the new oil control ring ... 4.04 mm to 4.07 mm (0.1591 to 0.1602 inch)Maximum thickness of new oil control ring ... 4.85 mm (0.1909 inch)When the oil control ring is installed in a cylinder liner with a bore size of 170 mm (6.7 inch), the clearance between the ends of the piston ring is the following value. ... 0.5 mm to 0.8 mm (0.0197 to 0.0315 inch)Install the oil control ring so that the gap in the spring is 180 degrees away from the gap in the ring. The white portion of the spring must be visible at the ring gap.After all of the piston rings have been installed, rotate the rings so that the end gaps are separated by 120 degrees. The ring gap for the oil ring must be aligned in the plane of the pin bore.
Illustration 2 g01212112
(4) Piston pin bore Pin bore diameter ... 70.0705 .0075 mm (2.7587 0.0003 inch)Note: Prior to assembly of the piston pin, the piston pin, the piston pin bore, the connecting rod eye, and the connecting rod pin bearing must be completely lubricated with clean engine oil. (5) PinThe piston pin has a groove on both ends. Outside diameter ... 69.93 .005 mm (2.7531 0.0002 inch) Inside diameter ... 30.5 0.5 mm (1.2008 0.0197 inch) Length ... 101.7 to 102 mm (4.0039 to 4.0157 inch)Note: The 263-8955 Piston Pin is not interchangeable with the former 197-0560 Piston Pin . (6) RetainerAssemble the retainer with the opening above line A-A.Refer to Table 2 for the part numbers of the tools that are used in servicing the piston.
Table 1
Service Tools    
Pt. No.     Description    
6V-4020     Piston Ring Expander Gp    
6V-4023     Handle As    
6V-4024     Guide Ring    
1P-1861     Retaining Ring Pliers    
1U-7616     Piston Ring Compressor Gp    
246-1176     Piston Ring Groove Gauge Gp (1)    
1U-6431     Piston Ring Groove Gauge Gp (2)    
( 1 ) Only for the top ring groove
( 2 ) Only for the intermediate ring groove