Red Baron Mike,

I am working on a 23.6 now slowly doing some mods to it trying to get some more power out of it. The thread that mikenlapaz mentioned does have alot of good info in it. There are some post from a guy named Keith user name BME he is the one that makes BME engines and I gues some of their engines are based from the Echo's (Kioritz). When I get time I will be doing some of those mods. With an electronic ignition he has them turning 8500 rpm with a 17-8 APC prop.
Let us know how you make out with yours.

Pete