1978 Johnson 4HP outboards Service Repair Manual P/N JM-7803, Page 55Get this manual

1978 Johnson 4HP outboards Service Repair Manual P/N JM-7803, Page 55

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Since the pistons, with the piston rings, receive the force of combustion in the cylinder head, it is necessary that both the pistons and piston rings properly fitted to form seal between the piston h