Hi Doug,
I've come across the left side only smoking mystery before....

When you park the bike up, do you normally use the side stand?

It can happen that oil pools in the head on the left hand side and then creeps into the cylinder head via leaky valve stem guides.

If the smoke goes away after it's run for a while or doesn't happen if you use the centre stand then that's the cause of the problem

Having said that, if you get smoke all the time then, as Legion said, you're looking at a top end rebuild I think.

Cheers!
Rudi