So today i broke in the engine on my tamiya nitro force. I ran 5 tanks of fuel through it without going full throttle. every time i started it it started on the first time and ran great. i brought it in, then about two hours later i went out to use it again. it took a few pulls to get it started and as soon as i hit the gas it stalled. i started it again and let it warm up for about a minute and it took off fine. when it ran out of fuel, i put more in and when i went to start it again the pull chord felt stuck. if i slowly pull it up it takes some force but it will come out and the engine will turn over. if i pull it hard enough to start it its gets stuck and it feels like im going to break it before the engine turns over. Does anyone know what could be wrong? Id like to get this fixed tonight if possible, i am dying to use it.