i heard of that tank prob being what was causing the engine idle failure. i tried at least 4 different tanks from friends buggies. just sitting on the frame while running. savage,mammoth, and 2 1/8 buggies. made no difference for me. what did was the cooling head keeping the temps way down. ran great. but still a traxxas engine. and a small block. had to go. i could have gone with the big block drop in option, but the running gear on it wasnt even strong enough for me with the 2.5. damn plastic gears!