my ax55 was/is unrealiable in the midrange (havnt tested it in a while), i got it to the point where it doesnt die but it lags so horribly in the midrange that its no fun for 3d. i replaced it with a gms .47 that was well broken in and much more fun to fly when you know a engine isnt going to crap out on you, and that when you give it throttle it actually responds instead of lags. imo i can hardly tell a difference between the ax55 and the gms .47 in terms of pull out both engines rocket the mojo out of a hover. the ax55 just a tiny bit faster than the gms but not worth the unreliablity and price (both turning 12.25x3.75 props)
my advice is get a engine that you trust. not a new one, one that has had some time on it one that you will bet $1000000 that it can last the whole flight, if you cant trust the engine on a 3d plane it is no fun at all, you worry about the engine not the manuver. it was such a relief when i was flying the mojo with the gms going into a low altitude hover knowing the engine wouldnt die/sputter.
if you want to use that ax55 put it on the plane u fly most (non3d plane) and have at it, after 5+gallons and your trust throw the ax back on the mojo and have fun.

i would get the mojo .40 its not that hard to build

Try an OS F plug in your .55AX....bet all your troubles will be gone-that is if its tuned right.

Having not run in the engine fully, I had a lot of trouble with it. Couple of weeks back, we ran a couple of tanks through it and then I had a full afternoon...actually 3 flights... before the weather got too hot and made us leave. Dont know if that sorted the problem, but it didnt deadstick. Didnt do 3D that day...was to scared to do it right then while the engine was still being probed. Also winds were opposite to what I am used to in hovering and I didnt want to endanger the plane or the crowd.

Will try to hover tomm...practiced it hard on the sim with a Reactor 160 with a FS200 engine. Hope I will be able to do it tomorrow but not before I pattern atleast two flights

Ameya

Had about 7 flights over the weekend. The plane flew quite well (read as one deadstick that too since I was on idle for too long before I went into the hover). I am getting used to the controls more in the mid rates (having started on low rates) and I hovered on the same settings. Also held knife-edges in both directions having never done that before ever in any plane other than in the sim. Needless to say that the Reactor inspires a lot of confidence.

One thing I want to know: I am using a 12x6 prop on my 55AX. We found that the 12x4 would make the engine whine due to being unloaded. But the side-effect is it keeps gaining altitude in the hover. If I throttle down, the nose drops. Also, I have a lot of difficulty in slowing for landing; a little of flaring and the thing keeps going down the runway. In order to land I am having to cut throttle everytime. Also in cruise, it gains speed quickly meaning holding level hover is difficult. Should I move to a 13x4 or 14x4? Think there is sufficient clearence for both.

Ameyam