Thats one thing I forgot to mention. Mine is cowled and I did have a big difference with the cowl on verses off. I solved it by drilling carb adjustment holes in the cowl and adjusting the carb with the cowl on. Since then, no problems. I also run a 28:1 oil mix, (klotz). For some lame reason I started my oil mixes at 50:1 and had overheating problems. A mechanic buddy recomended more oil and thats what utimately solved most of my problems. It would run uncowled, but not cowled. I am amazed at how much punishment a ryobi can take and still run. I know I did some damage to it but it starts pretty good and runs reliably thru the entire flight. I set my flight timer for 15 minutes cause I dont want to stand around any longer than that and use about half a 16oz tank. Will definately use a smaller tank next time. There IS one issue that I havent figured out yet. I have to raise the tail of the plane level with the ground to choke the engine. Lower the tail and then it starts. If I dont do that, it wont choke. Hope I dont have that problem on the next ones.
Edwin