Question regarding a 2000 400EX. Long story short, the quad had a running condition where it would stall when applying the throttle. We found a problem with a connection causing a weak spark condition. We fixed this, but in the process, rebuilt the carburetor thinking that it was the problem. Now when trying to start the machine, it will start with the choke, but only run for a few seconds while manipulating the throttle to try and keep it running. I had turned the idle mixture screw out 3 1/4 turns as this is what is was set to before the rebuild. Could this be the problem, or is there another adjustment that needs to be made? Also, is there a fuel filter inside the tank on the petcock. There is no inline filter on the machine.