its not an engine tuning problem i will garentee that!!! i have two of them, all you ahev to do regaurdless the transmission case color they both adjust the same. even if you have the new transmission crontrol that the newest t-maxx has they both adjust the same. if you think it is stuck in 2nd gear then all you have to do is find that set screw through the window there and tighten it that will allow for the engine rpms to get higher before it shifts. what i probably is doing now it because the screw is too loose just the idle of the engine probably spins the tranny and puts it in 2nd gear, so just tighten that screw up alittle at a time and go out and take it for a run down the road and if it still dont shift tighten it alittle more until it does shift.