81913M Mariner KEY,CRANKSHAFT TO FLYWHEEL...

Illustration 1 g00642351
Note: The word "Front" or an arrow which is marked on the piston crown must be toward the front of the engine. If the piston crown is not marked, put the narrowest side of the piston crater toward the side of the engine with the fuel injection pump. The shortest distance between the edge of the piston crater and the edge of the piston is the narrowest side of the piston crater.Note: Ensure that the ring end gaps of all the piston rings have 120 degrees spacing from each other.Note: Refer to the Systems Operation, Testing and Adjusting Module, "General Information" topic for the location of the serial number plate. (1) Top piston ring Shape of the ring groove in the piston for top piston ring ... Parallel Shape of the top piston ring ... Parallel Width of the ring groove in the piston for the top piston ring ... 2.60 to 2.62 mm (0.102 to 0.103 inch) Thickness of the top piston ring ... 2.475 to 2.49 mm (0.097 to 0.098 inch) Clearance between the ends of the top piston ring in a cylinder without any wear ... 0.28 to 0.51 mm (0.011 to 0.020 inch)Note: When you install a piston ring, make sure that the word "TOP" is facing the top of the piston. New top piston rings have a red identification mark which must be on the left of the ring end