A lubricating system for a reciprocating machine such as a two cycle internal combustion engine having the cylinder bores horizontally disposed. A drain system is provided for draining lubricant from the lowermost crankcase chambers to the upper cylinders so as to maintain uniformity of lubrication and insure even and smooth running. A check valve is provided for precluding reverse flow and the lubricant is delivered both to the crankcase chambers and to the piston through either the piston and/or cylinder liner. The lubricant supplied to the piston is supplied at its upper area so as to insure complete lubrication of its circumference and of the associated cylinder bore.