Michael: Not enough information in your post. Does it smoke on a continuous basis or only after you start up and then the problem goes away some time after it's running for a while? Also, are you using the specified SINGLE viscosity oil or a modern multi-visc, which is "thinner" when cold?
Does a faulty oil ring on the piston have anything to do with the smoke? I am also facing this problem now and just don't know what the problem might be and what is the right quantity of oil for the oil tank?
There are so many potential causes for an engine smoking some detail of symptoms,work carried out and history of the engine etc. is needed..
For example..Worn piston/bore, worn/broken piston rings, worn valve guides, oil 'pick up' problems in the crankcase, wet sumping, drainage problems in the valve pockets (some OHV motors) and excessive oil supply to the valve gear on some types...Ian