I have a 92 l/c EXT550 that was running fine. Then one day it started to miss and sputter at higher RPM's when I hit the throttle. The wierd thing was I was able to gradually ease into the throttle and hit top speed. I replaced the fuel filter, rebuilt the pump, plugs, and put de-icer in the tank. Also cleaned and synchronized carbs, and now it will not draw gas to the carbs. I may have used the wrong pump rebuild kit, will that make a difference? Any suggestions?