I just rebuilt a 2013 kx250f for a friend. I put all new Moose valves and springs with a new Wiseco piston and gasket kit. I had a professional mechanic cut the valve seats and I put everything together very carefully. The bike runs fine but it wont idle. I started it up with the choke and it ran like normal but when I turned the choke off the bike's idle dropped down and died. I was able to start the bike without the choke if I gave it a little throttle. I turned the idle way up, if I gave it a little gas it would idle for a couple seconds as if the throttle was hanging and then it would die. I checked all the electrical and reconnected the wires. I may have overlooked something? Any help would be greatly appreciated! Thanks!