Last fall my 1945 M20 was running great. I tried to take it out for the first spring ride and when it was warming up I noticed oil pumping out the crankcase vent tube. Any ideas?
All sorts of fixes will be offered, ultimately though the only way you can be certain it wont do it is to take the oil out, my bikes that are prone to it get drained if going to stand for more than a few weeks, by using a tap on the drain outlet. I just let it drain after parking through a tube into transparent recepticle that has a loop that slips over the footrest.
That way i remember to put the oil back in before riding it or fresh oil if i feel its too discoloured.
It sounds drawn out but its very simple to do & running an engine that's wet sumped is bad for the engine.