My 1999 YZ400F that I just got did not idle well so I tore the carb apart and of course if was dirty, but after putting it back together, it still did not idle that well. I looked at is closer this time and found that the thin part that makes up the throttle valve is cracked: http://home.csumb.edu/s/simpsonhenryk/world/carb.gif It is the part that looks like a lid on the skateboard that combined is the throttle valve. Anyone think this might be the problem? Above idle is rips just fine but at idle is dies and if I keep the throttle on to keep it running, it seems to pulsate. Anyone ever seen this and I am thinking of getting a newer carb for the bike, so can someone tell me what fits/works? Oh, and great to meet all of you in this forum. Been around in the DRZ forum, but when I got back into the dirt, the YZ was a lot less than getting a DRZ and seemed like fun.