i have an older T-MAXX, and i have been having problems with it lately, i can get it to start, but then it sounds like it is accelerating and then begans skittering. when i try to give it throttle, it will shut off. whats wrong? thanks

I also have an older t-maxx its the 2.5 though. I didnt run it for 6 months but now that i have time again for it im haveing simalar problems. When I hit the throutle it would shut off to, but i tuned the high idle screw and that fixed that. My Engine is over heating but i think i just need to tune it some more. My big problem is it goes with out me useing the throtle. and the carborater isnt open! My T-Maxx is also not getting alot of power, and its modded and even a raceing piston. Can some one help me and the other person please?