Problems w/ Motor?

Does anyone else have a problem where your motor will have a fluctuation in the rate of fire? Like it'll start off fast then get slower and stay at the slow speed for about 20 shots then get faster?

well, my gun completely stopped working today. its not the battery, so im sending it back to HSA to see what the problem is. The motor isnt even trying to turn, but if i let it sit on safe for two minutes i can pull the trigger twice and it it'll work for two shots, and it'll work on full auto sometimes just fine until i let off. the holes in the sector gear are clear, its just weird.