My 2004 ski Doo gsx sdi (fuel injection) model has a fuel problem. Just went through the entire sled all is set. But once the fuel tank gets to or below 1/2 tank it will stall and spitter at high rpms. Idles perfect still. Put a fuel gauge on it, rode it, and the pressure drops. I took the pump out and checked all the lines... All seems good. I do know this pump style was a one year thing... Starting to realize why. This pump has the internal lines and fliters. The models after were direct into the pump. I think air is getting in mid line filter once the fuel level gets lower. I'm out of options? Please HELP!