The history of this bike is it was bought new in 2006, wrecked with 1,940 miles on it . It has sat in the corner of my carport under cover for 15 years. I just recently decided to bring it back to life. I have it started and road around the yard. Now it's puffing white smoke out the exhaust, when I remove the oil fill plug, I can feel air blowing out it. Ideas?

 

Now I am puzzled, I am just out from cranking and running the engine and could not reproduce what it did earlier today. No smoke, no stumbling. I rev it and it responds like it should.

 

Stuck oil ring maybe?