I wager it broke a piston ring on one side and is oiling the exhaust pipe down on that side.

last one I had smoke on side and still ran good..for a short time anyways..it was detonation eat away the piston to expose the top ring and sarted a melt down in theat cyl.

didnt take but 2 more runs to kill the piston and leave the pin/rod in the hole banging around...staill ran and had oil pressure but made one heck of a noise.

I will be swaping the 440 rpmintake off mine for a hollet street dome to run the q-jet with out the adaptor. PM me if intersted in it.