I have an 01 ktm 300 mxc. with a pwk 38mm carb. .I am in the process of changing jetting. I am at stock jets right now 45 pilot and 175 main. I have the needle at the lowest postion to lean out the mixture. it still run a bit rich . Should I go to a 172 main and put the needle in the third position? Also the idle is a bit rich if i changed the pilot to a 42 would that be smaller or larger jet?