I have 450 yfz 2005 with less then 1 hour on it. After riding it for the first time I was so disappointed on it's low end and overall performance. After asking around I heard that exhaust and rejetting makes a world of difference. So this is what I did. BUB Moto C4 Carbon Fiber/Titanium System K&N Proflow w/o lid 175 Main jet NCVQ on 7th position Stock pilot 4 turns About 825ft above sea level It still lack in the low end and runs a little rough. Any suggestions? Also while doing all this I unhook my tps (throttle position sensor), and now I'm not sure if I hook it up right? HELP ME PLEASE!!!