I just had a bad gallon of fuel, and due to my disbelief that the fuel was bad I may have smoked my YS 120. It was a brand new gallon opened minutes before I put it in the plane.. see my ongoing saga here..
http://www.rcuniverse.com/forum/Bad_...2810049/tm.htm
I believe the fuel was missing at least oil content, because there was very little oil on the wing. Unfortunately I may have tried to hard to get it to run on the bad stuff before realizing it may be the fuel. Now I"m afraid of the repair bill....