RE: cermark mb-339 arf question?
Mine has 200 flights, mostly P-80 and lately P-70. Usually fly at half thrust maybe 8-10lbs, and it takes off nicely at that setting and flies effortlessly. Full power occasionally only for a low pass or some vertical but it doesn't need it. No bypass in mine. The bouncing will go away if you use some knee action struts like the Intairco short nose strut on the mains. Also dial in some crow on the ailerons.