I'm a born 2 stroke guy. I have just bought my first Saito. It's a 72. I guess I have yet to see the performance I've heard of. I'm going to check valves and re-tune the needles. I'm not giving up on Saito, but my next project is either going to be a 91FX with a Jett Muffler or a Saito 100. The Saito is 4 ounces lighter. The 91 seems to make about 2000 RPM more at top end. I rarely have trouble tuning a 2 stroke purely by ear. The 4 stroke seems a bit touchier to get right. No doubt once it's tuned and valves are set, it will give little trouble, but will the power be there? The new plane (with the 91 or 100) is going to be a GP G-202 46 kit. I'm sure I can build it below 6.5 pounds with either engine. My prop choice will be a 15x6 or 14x6 APC depending on the engines preference. Somebody convince me to go one way or the other. I'm not looking for an engine bashing thread, but I need good and bad. Also, what do you think about running Wildcat 20/20 4 stroke fuel in a 91FX?