816819 Mercruiser BALL BEARING

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 gap when the top piston ring is installed on an upright piston. (2) Intermediate piston ring Width of the groove in the piston for the intermediate piston ring ... 2.56 to 2.58 mm (0.101 to 0.102 inch) Thickness of the intermediate piston ring ... 2.48 to 2.49 mm (0.097 to 0.098 inch) Clearance between the ring groove in the piston and the intermediate piston ring ... 0.07 to 0.11 mm (0.003 to 0.004 inch) Clearance between the ends of an intermediate piston ring in a cylinder without any wear ... 0.30 to 0.63 mm (0.012 to 0.025 inch)Note: When you install a piston ring, make sure that the word "TOP" is facing the top of the piston. New intermediate rings have a green identification mark which must be on the left of the ring gap when the intermediate ring is installed on an upright piston. (3) Oil control ring Width of the ring groove in the piston for the oil control ring ... 3.53 to 3.55 mm (0.139 to 0.140 inch) Thickness of the oil control ring ... 3.47 to 3.49 mm (0.136 to 0.137 inch) Clearance between the ring groove in the piston and the oil control ring ... 0.05 to 0.09 mm (0.002 to 0.004 inch) Clearance between the ends of an oil control ring in a cylinder without any wear ... 0.30 to 0.63 mm (0.012 to 0.025 inch)Note: A pin is used in order to hold both ends of the spring of the oil control ring in position. The ends of the spring of the oil control ring must be 180 degrees opposite the end gap of the oil control ring. (4) Piston pin Diameter of new piston pin ... 39.694 to 39.700 mm (1.5628 to 1.5630 inch) Bore in piston for pin ... 39.703 to 39.709 mm (1.5631 to 1.5633 inch)Piston height above cylinder block (not shown) ... 0.36 to 0.50 mm (0.014 to 0.020 inch)