smoking Triumph Speed Twin

I purchased a 55 Triumph Speed Twin about 2 years ago. The previous owner had the engine rebuilt about 10 to 12 years prior to that. When he went to register it the state said there was a "issue" with the title, he never pursued the issue. As it turned out there were 2 trailers with the same Vin number. So this bike sat for all those years and never run,and it smokes. I expect that when the engine was rebuilt the rings were oiled up, with modern oil. That is just a guess. So when the bike is started it smokes like nobody's business. I don't want to pull the engine down if I don't have to
Any ideas?
John in Texas

Not much Commando content ere !

Have you tried draining the oil out of the sump ?

Try going for a ride on it.

Check the Oil return .

Stuck ball valve in pump , or coagulated return line .

Yes , pull the sump plate . May be a tarantula stuck in the pipe .

Best thing you could do is trow away the trash like mufflers & guards & fit a slimline Gas Tank & spoon seat .