Quote: Originally Posted by 2leftover
Hi, I have a 2002 400ex that I can't get to idle without bottoming out the throttle stop screw. The pilot screw has he effect. It appears to be rich on idle but I can't find any air restrictions. It has an after market exhaust and a K&N air filter. It does have the stock jets (main & pilot) and the needle jet is clipped on the third from the top. The plug is black and the fuel smell at high idle is strong. I can pull the vacuum line from the intake side of the Carb and it smooths out. Been through the Carb numerous times with cleaner, fine wires and compressed air all with no changes. I've check the valves and found no problems either.
Any suggestions will be greatly appreciated.
vacuum line smooths it out?? do you mean the crankcase vent line ?
ifso, it sounds like your air filter is dirty,
remove your filter and see if it idles, make sure inside air box is clean