Sunday,,Oct 4thwhile flying in the Ringmaster thingy, I was getting my OS .25 LA engine ready to start when Ronnie Thompson said my engines head was on backwards. Sure enough. It has been that way for 9 months. That's how long I have had it in the Super Ringmaster. Only thing I did to it after getting it of Ebay was to install a metal back plate and an OS needle assembly. Runs fine.Good thing the combustion chamber is round... Oh, and I'm leaving it alone.