The oil is fed from the oil tank to the pressure side of the oil pump.From this point the oil is forced through drilled passageways to the crankshaft and from the big end the oil issues in the form of a fog to lubricate the pistons.
After lubricating the engine, oil falls to the bottom of the crankcase where it is filtered.
The oil returns to the suction side of the oil pump to the oil tank.
The suction oil pump plunger has twice the capacity of the pressure side, in order to make certain that no surplus oil remains on the floor of the crankcase.
To lubricate the valve rockers, oil is taken from the return scavenge pipe by tapping the supply just below the oil tank.The oil , after being forced through the rocker spindles, lubricates the valve stems and push rod cups.
After this the oil drains to the push rod cover tubes, where it then lubricates the tappets and finally drains into the sump.
