Hey Nappy99 , Did you ever figure out your problem with the AX ? I have the .75 with the same issue . Ended up quiting after a touch and go and I had no safe place to land and tore my front end off my
Aeroworks Edge 540t . It was sputtering at 1/2 throttle and I gave it full and it died right away at about 50 feet when I was making a turn .

I have a .46 ax and it wasnt so difficult to tune. The .75 seems like you can keep turning the top end screw in and in and the RPM's keep climbing to no end . So I dont know if I got it to lean or not . The motor also puts out a lot of vibration putting bubbles in my tank . When it ran without quiting there was hessitation from low end to top end and that was after turning the idle screw out 1/2 turn . I wasn't getting a steady smoke stream either . It was intermitent . I was running a 14X4w APC on it and used a Hayes 16 oz. tank . How do you know when you are getting too lean on the top end when it does this ?