left cylinder smoking

I just picked up a 70 fastback that has been sitting for 18 years. I completely flushed out the primary, clutch, oil and fuel tanks. It has a boyer and a 34 mm single mikuni. It started fine and runs great but after it's warmed up the left bank starts smoking. I know the bike from years back and there was no smoking issue when it was last run so I suspect maybe stuck rings. Any suggestions?

I hesitate to comment on anything based on some PM shit I've received from a fairly new forum member but I would dump a bunch of Kroil down the spark plug hole and see if it frees up after a couple days. How far have you ridden it? It should free up after a while if that is what is causing the problem.

Russ

Haven't ridden it at all.

Sometimes the valves left open to atmosphere over time rusts one side more the other. Smoke while cold-ish implies rings to me and hot smoke, guides but could just be gasket or porous casting finally breaking through. Traditionally - smoke on throttle > rings, off throttle => guides.

Only two ways to find out for sure, run it till show stopper, then look in or just look in soon as practical.