Estradajae, the original engine I was having issues with is gone and I have a replacement for it hence the original question. I haven't flown the new engine yet but I may try next weekend weather permitting. The fuel being used is Wildcat Premium Xtra 15 % nitro, 18 % oil and the prop is a Master Airscrew 11x6 wood. And as stated in my previous post I tried everything possible to get it to run right. Even Evolution tech support couldn't get it to run right so I don't think I was doing anything wrong. The reason for a Saito is the sound and the power as well as fuel economy.