I bought a boat recently with 1998 yamaha 150 that performed well for about 10 hrs. Last time out when after about 10 min of running when I went to full speed (5500 rpm) motor made higher pitch noise and lost power then stalled. Would not restart. Tried two minutes later and started ok. Repeated this process about 5 times and took back in. Last time lost power at 3000 rpm and died. Changed fuel bulb and inspected and cleaned fuel filter. Any other advice would be helpful. Thanks