need a little knowledge here?

so heres a question for you guys im runnin a jammin truggy, nue 1515 1y geared 13/62, mm settings are default basically, all different types of batteries that i know are fine, but anyway i was running at pheasant runn today and i noticed a loss of power, at first it was for the first few laps then it would be fine, then at my track later it was doggy the whole time, not real bad just not as rediculous about 60% worth, but temps are fine on everything, nothing is binding? rechecked my settings they were good, put a rx pack in, still did it? anyone care to shed some light? motor goin? mm messed up?