1978 skinautique

Boy, first post and you've been ignored for over 24 hours.

You have quite a few choices as to why the boat runs good up to 3000 rpm and then quits

If it quits because it's starving for gas it could be your fuel pump, it could be whatever you have for fuel filters being restricted enough to let it run up to that speed and then not allow enough flow.

There's also an anti siphon valve on top of your gas tank that could be plugging up enough to restrict fuel flow.

You also might have a fuel inlet screen right where the fuel enters the carburetor but in the last 39 years who knows if it's been removed or is still there.

An easy thing to do to narrow down the problem is to hook a temporary gas supply to the fuel pump inlet and run the boat.

If the problem is gone then your culprit is the suction line upstream of the anti siphon valve being restricted (usually by junk from the tank), the valve itself, a restricted suction line between the tank and pump or a restricted filter in the line if you have one.

If you still have the problem with the temporary hookup, then you can narrow it down to the fuel pump or carburetor having issues

If it floods easy, it's probably time for a good cleaning/rebuild.

Then again you could have ignition issues making it cut out at about 3000 rpm, but I'd do the temporary tank setup with a gas can and a short length of hose before doing anything else and see what your results are.