dear matt,
with that miligned setup, you will have to make adjustments to talor one type of ridding style. you see the 2 stroke us designed to depend highly on the scavenging effect providded by exhaust backpressure and reflective pulses from the pipe. the factory setup was designed for all around riding and the more you mess with that to gain power where you want it the more it will only work right there. baisically, when you tuned the carbs, it was not "warmmed up" to how you are gonna ride it. i think your exhaust is pushing air that is too hot for the mixture back in to the cylinder when it's warmed up. what i would suggest is to moove the needle 1 or 2 knotches richer (mid throttle) pull the silencers from your cans, and go up one jet size. you may also have to swithc to br9 plugs if they glaze (look wet but aren't) also you will have to ride the engine harder most of the time, 6 tanks of gas is a granny break in. just cruise around with 10-15 second hard accelerations every 2 min should have had it broke in within 25-45 min (you'll feel when the rings seat- it's awesome)