50hp 4 stroke evinrude rpm fluctuate

[walleye5179]

I've replaced hose and bulb,both fuel filters,plugs and fuel pump.I seems to be starving for fuel?This happens at full throttle,and some times when I'm trolling slow at 2 mph it will die,but it always starts right up again,and this is intermittant doesn't happen every time I take it out.Yesturday I went 2 miles outta my fishing spot an it did it and I noticed if I lift up on throttle it would go back up to normal rpm,on my back later it ran flawlessly

 

[jakedaawg]

For the die at idle clean the idle air bypass port on the throttle body.

for the rpm fluctuations at high speed: place a mark on the prop and a corresponding mark on the hub. Run boat till it fluctuates. See if Mark's are still lined up. It may be as simple as a hub slipping.

if the fluctuations are more like a switch flipping that's usually bad plugs. I know you replaced them but here in Michigan it's not uncommon to run into a new plug that's bad right out of the box.