I have a YZ400 and it used to ride fine before the winter, I stored it incorrectly and now it won't run. I cleaned the carb and it would fire up but when ran it would always stall, and when it would run it would back fire alot when the throttle was put on steady. So I sent the carb in again to have it cleaned and they "reset the carb to stock", and now I can't even get it to start. Before it was reset the clip was way on the rich side, and the fuel screw was about 1 3/4" turns out. When running it would get hot reallly fast, and would only run on the choke, so I turned out the fuel screw 1/4 turn but nothing realy changed. The valves are in spec, and has a new plug. I am trying to sell the bike but want it to to run right before it sells.