aero nut, Thanks for starting this thread and thanks to all who have shared so much information, a lot of it over my head! I've been playing around with a 25cc poulan with the stock mag. ignition...A 28/32 venturi wabro carb is the only mod... I get 7,000 RPM on gas using an 18x6 APC prop, didn't think that was too bad considering the small ports and low compression this engine has... Today I put the glow adaptor in and ran it on straight 93 octane 40 to 1 gas oil mix and it ran same RPM with glow power on... Just for grins I had some 30% heli fuel I use in my Saito's and added that when gas was down about 1/3 of the tank... I know I had wayyyyy too much oil but this engine ran great after getting the carb set correctly, only needed glow power to start engine, idle real nice at 1900 and was turning 7300... Next thing I did was remove flywheel and got 7500 RPM with way quicker spool-up... This engine has very little vibration and no detination even with a lot of nitro, probably do to a little less compression than some engines... Tomorrow I will remix and get rid of some of the oil and see if that helps a little more...This engine weighs a little less than 40oz with muffler and mount ready to fly, should work good on a Funtanna or something like that... Thanks again for all this great info here!!! Hamman