Amazing! I should have known something was up when it only bogged down after hitting a bump. I just re-read your entire original post now and saw that bit of info. So... the brake was actually being applied by itself at times. Wow! Glad you got it solved!
Id check the valve clearances... the "lash" as they call it. Check YouTube how to do this. Then i would raise the needle that goes into the main jet by moving the c-clip down one notch. That gives it more gas under a load. Never had a warrior but most yamaha carbs are pretty much the same unless...
