1980 Ski Nautique Starving for Fuel

[Jbraddon]

I rescued this boat. I’m going to restore it, provided that the mechanicals are good. After two water tests, they are. It’s the exact sister ship (incl color) to the boat my dad owned from 1985 to 2015. It hasn’t been run in 2 years. It has a new starter, start solenoid, plugs, oil, gas (with SeaFoam) and gas/water separator. Boat idles and accelerates up to 3000 RPM as it should. Any time above 2000 RPM, it bogs down and acts like it’s starving for gas after about 200 yards. I back off on the throttle and let it idle for 30 seconds and hit the gas again and it repeats. As it’s bogging down, I bump the throttle quickly to activate the accelerator pump. That doesn’t help as there’s no gas for the accelerator pump to squirt down the throat. The gas tank breather is clear. The gas tank is nearly full. I ran the boat for about an hour with the same issue repeating.
I suspect that the rubber gas line from the tank should be replaced as it may be sucking air. It could be restricting flow. There is no gas in the bilge and no gas fumes so no leak. I think that the fuel pump is ok as it supplies fuel very well to get it up on plane.
Any help is appreciated.

[Jbraddon]

I have just realized that the fuel pump has been replaced with an automotive type. I’ve ordered the correct pump. I’m replacing it even though this may not be the issue. the new pump has a barb fitting that needs to have a tube up to the carb. Does anybody have a picture showing this?
It could be the check valve at the tank or a clogged pick up in the tank. I’ll probably pull the tank. Is this difficult? What’s the best way to get the gas out of it? I assume siphon out from the filler tube. I’ll replace the gas line also.
Going back to my fuel starve issue, it could be the carb. Maybe the float is sticking so fuel can’t enter the bowl. If that’s the case, why would it consistently unstick when I idle? It seems like it would continue to stick once out of 10 times.
overall, it seems to be a weak fuel pump so I’ll eliminate that first. Thanks

[SilentSeven]

That's a really pretty boat!. Should be a fun project!

Regarding your problem...I think you should just plan to refresh the entire fuel and ignition system end to end- the boat is almost 50 years old and you'll appreciate the reliability. Seems like you're pretty much on this plan already.

As to your specific questions, you might also want to post on correctcraftfan.com. Seems like there are more vintage Nautique owners on that forum. But please don't stop posting here as we'd love to watch the progress!

[SilentSeven]

To eliminate the fuel tank / pickup / lines as a source of the problem, consider running a temporary fuel line from your new pump to a 5 gallon fuel can with fresh fuel and see if that resolves your 3k RPM issue.