I have an "89 Sukuki DT 150 on my Aquasport 222. It'll start and run 3500-4000 RPM fine for about 5-10 minutes, then it bogs down and usually dies. The primer bulb is completely flat when this happens. The only way I can get it to blow back up is to disconnect the fuel line between it and the tank, then re-prime it and it's OK for another 5-10 minutes. Does this sound like a bad ball?