Home › Forum › Ask A Member › Johnson AD needs help › Re: Johnson AD needs help
That motor actually has an oil pump. Don’t laugh, it does. See the key slot on the lower main journal of the crankshaft? Now look at the lower main bearing. See those two little holes that align with the key slot as it passes by? At that moment, there is pressure in the lower crankcase section. The pressure forces oil that has accumulated at the bottom through those passages & keyway, through the hose to the upper main bearing, where it spills out to lubricate the upper bearing (where there is a partial vacuum at the moment). And of course it then enters the upper crankcase chamber to do its dirty work, if it contains water mixed with the oil. The 12hp in the other thread is oiled the same way.