Hello everyone, I used to be on this forum but just got back into riding recently due to recovery from an injury. I bought an 07 WR450F that I made into a dual sport to ride around town and up to the woods. I'm having major issues with it that I can't get figured out and I'm getting really frustrated with it! A little background, bike seems like it was barely ridden and is very clean. Had an FMF ti powercore slip-on on it but because I was buying it to ride on the street I asked the small motorsports dealer to put back on the factory one (they had it) and rejet back to stock (maybe a big mistake?). I put the street legal kit on (Tusk) which included redoing some of the factory headlight wiring, but other than that doesn't connect to factory wiring at all. My first ride I started having issues. Started at constant throttle and is best described as cutting out/missing. Then as the bike got hotter, it started doing it across most all rpm range. Always noticeable during smooth acceleration. It is hard to describe how bad this problem is. The bike is really almost unsafe to ride because it is jerking/cutting out so badly. Things I have tried so far: first I changed the spark plug. No difference. Then I tried unplugging the TPS. Bike was quite a bit better but still very very noticeable issues. Just tried today to put back on the FMF exhaust, and if anything it's worse. Any help is greatly appreciated. I have quite a bit of money tied up into this bike right now, and can't even ride it! Thanks.