Launched boat, start engine run a few seconds and stop would not continue running. Next day engine started,strain engine to get boat on plane. sound like engine running on three cylinders. once on plane at 4000 rpms tack would go up to 4200 rpms and back down to 3500 rpms. Change primer bulb,2 fuel pumps,gas element filter. Launch boat started fine, would not get boat on plane, rpm at 2200 with throttle w.o.