Well everyone can look at my set up I took it to sand montain and let it rip, the predator that used to beat me has a WB pipe K&N Blk box and jetted would beat my piped K&N stock 400ex fairly easy by at least 75 yards going up the montain, now with all the mods I have listed WOW what a rush, I hole shotted the predator stayed about a wheel in front until about the last 50 yards he would pull me to a bike lenght win, the same results 3 times, I do have a problem when I stuck with the factory bore went to compression piston and a stage 2 cam.....the problem....I lost all low end totally, I'm going to go two teeth larger in the rear sproket to see if it helps out, if not I'm going to have to bump the 400 to a 440 to bring back the bottom end, thats what hurt me when I raced the preddy I lost speed at the end due to loss of low end grunt at the top of the montain.

Does anyone else have any other ideas to help the bottom end grunt, I was told that if you change the timing on the cam that could change the low end tourqe has anyone ever did this and can it be done on a 400ex?