I’m having an issue with my 598. It’s carbureted, has a quick few 1050 on it. It starts right up, but won’t stay running have to keep Goose in the throttle to keep it going. I took the carburetor apart cleaned it put it back together seem to fix the issue in the driveway. Took it out today did the same thing I got about 200 feet out and it had the same problem with would not idle and had to feather the throttle to get it back to the dock.

List of stuff I’ve done. Clean the carburetor metering block jets, thought I might’ve had bad gas so I drained all the gas out of the tank replaced with new. Not sure what else it could be seems like it’s getting plenty of fuel to the carburetor, I have 6 1/2 pounds of fuel pressure. With it having 6 1/2 pounds of pressure it seems unlikely it would be a fuel filter or water separator issue but I could be wrong Help

Also, it won’t even hold RPMs. So if I managed to get it up to 2000 or 3000 RPMs and leave the throttle alone it will also die

Replace or at least dump out the water sep filter. If its 90% full of water, what you describe can happen.