My 2004 60 hp EFI 4 stroke looses power at full throttle but runs well at lower speed. When I start the boat I am able to get to top speed but after about 30 seconds the motor slows, (RPM’s lower). If I shut it down and unplug the high pressure fuel pump, turn the engine over, plug the pump back in and restart it I can go for another 30 seconds to a minute, then it slows again. I can repeat this cycle as many times as I want. I have replaced both fuel pumps,( high and low pressure) all filters and plugs. I have checked all fuel lines and replaced one. Pressures off both pumps seem fine. There are no warning codes / beeps except the normal on at engine start. I also replace the voltage regulator last year after it caught on fire.
