Hi, Mike. Have you experimented with the jetting? Also, if you use the stock head pipe, check the weld between the flange & the pipe. Mine was built up 1/8"+ all the way around. A die grinder got rid of that. I'm also running the vortip, though a little less modified than yours. It's just strange that it takes away bottom/mid but pulls strong on top while restricting flow. I'm hoping I can jet the bottom back in. I'm just really slow. I'm currently at: DVP#4, 175 main, 45 pilot (too lean, soon to be 48), vortip with tube ends thinned & flared, YZ cam timed, airbox lid gone, octopus retained, gray wire pulled. @ 1000-3000 ft. This summer I've committed myself to riding w/vortip. The power was perfect without, but just too darn loud. ------------------ tbronco 98 WR400 Dualsport!