I'm using this engine on my first plane, GP Big Stik .40 it has a lot of power but not reliable, my problem is the engine keeps dying on me. Not very confident with it, I'm sure it's just my needle setting. I like doing low fly bys and usually the engine dies when transitioning from idle to 1/2 throttle. Luckily I'm right above the runway when it dies and I can save it. But my last dead stick, the wind was blowing hard had to turn the plane around didn't reach the runway and it went to the trees. Just a little tear on the wing. On the bench there's a good transition and everything seems fine. I'm using a 12 x 6 APC, tach it around 11,800 RPM WOT and idles around 2,600. Vertical is insane. I stop using the Tower plugs and switched to OS 8. (got free plugs with this engine). Since then I had about 3 flights now with no dead stick. Keeping my fingers crossed. I almost gave up on this engine and was going to put a 4S in. But I'll give it another chance....