I just put in a whole new top half of the engine on my 02 kx 125, but i used the old power valve. I cleaned it as it was covered with carbon, i put it in as the manual told me to but it seems to be very nosiy at low rpm, it clicks but i have no problem with power. does anybody know if this is normal or a bad thing?

also i have another question about riding, when the (good) motocross riders jump, they almost always seem to take there foot off the peg and move it back to the swing arm. why do they do this?