I took the boat out to the ocean today for a little fishing trip.i noticed that when its wide open the rpms go to 5200 max.after it runs there for about 20-30 seconds the tach starts dropping down to 4400 and seems to stay.if i pull back on throttle for a minute or 2 it will pull back up to 5100 and start the same process over again.sounds like it needs more fuel on the upper rpm range.i replaced the filter on the motor before leaving and it looked fairly clean inside the jar.i am goint to check the fitting on the tank and hoses leading to the water separator.supposedlt the injectors were cleaned and high pressure pump replaced last year. But i have no proof.just a say so.starts and runs excellant other than that.any help appreciated.