Mercury 50 hp backs down at 4300 rpm to 3000 rpm

[dcwshl]

I have a 2002 Mercury four stroke 50 hp. When I reach around 4300 rpm and try to go faster the motor backs down to around 3000 rpm. What is causing this?

 

[steelespike]

Re: Mercury 50 hp backs down at 4300 rpm to 3000 rpm

Welcome,you really need to put this in the mercury section this is props.
My guess is an oil pressure or temperature sensor.