This problem is not very big, being that I am still trying to hover, not fly, and I have not really fooled around with it a whole lot yet, so I could very well figure it out on my own, but would still like some tips. Generally I should probably have someone who knows what they are doing look at my engine, but just don't have the time to schedule an appointment right now being that I have started college and work is very busy. But when I first start my heli, it is running fine, but then when I start moving the throttle up it will lift off the ground and hover, but after a few hops of running for maybe 5 minutes, its like it loses power and at one point I had it to full throttle and it was barely lifting off the ground. I would play with the engine mixture valve and it is like that would fix it for a while but then lose power again. I try it rich and then I would try it lean. Should I adjust the speed valve more? I dont want to keep messing with the speed valve too much, but maybe I should still try something. Before it was not getting any power at all and even shutting off at full throttle until I adjusted the speed valve now it does not shut off at full throttle, but it loses power after a while as if the engine is getting too hot, but it does not appear to be hot. Could the type of fuel be a problem too. I have a Raptor .30 with an O.S. 32 engine and by a mistake got the 30% heli mix nitro wild cat fuel. Should I try 15%. Everyone else seems to be using 15% but just thought maybe I could keep using the 30% until I use it up. Let me know your thoughts.