hi everyone. hope you're all doing well... i have a pothole on a nearby hill that i use to gauge my low end power with. when i put on any new part, i run up the hill at full speed and see how far it gets past the hole. i put little chalk marks to compare with my gps info. if they correlate, we have a winner. anyway, i recently checked my mountain bike and found that it seems to be loosing power. i cleaned the carb and gave it a general tune-up. double checked for leaks, and so on. i even got a SBP expansion pipe, but it still wont make it to it's highest point ever recorded, even with the SBP pipe. as of now, it has around 2500 miles and still runs like a dream, other than this issue... my top speed on level ground doesn't seem to be affected at all. what could cause it to gradually loose low end power like that? what am i missing?