Does this sound like belt squeal or like something more severe?

Haven't taken the boat out in a long, long time until this morning.

Fired up right on the 2nd try and this is what we heard:



Does this sound like belt squeal or something more severe?

Sounded like belt squeal to me. Stick your finger nail in the side of the belt. IF it does bounce back to it needs to be replaced. Also, do those black scorpions have an alternator with a adjustable bracket to pull out the slack or is there a tensioner. I guess it could potentially be a bad pulley/bearing somewhere.

I have a Sanger 215 that did this exact same thing, check the bolts on the alternator, 1 of mine was sheared off causing a slight change in the alternator angle.
It did it at start up only. I was lazy and never checked it out for 3-4 months, finally got around to investigating it to find the sheared bolt being the culprit.

Sounds like belt squeal, but you'll want to find out why and fix it. Doesn't seem like any fun to have it burn up while out on the lake. My 04 black scorpion has a tensioner pulley. Could be the alternator, raw water pump, water circulation pump, or either of the two idler pulleys. I would pull the belt off and spin the alternator and idler pulleys by and and push them back and forth looking for play in the bearings. Could also just be an old belt.

If you take a bar of soap and hold it against both sides of the belt while it is running it will stop the squealing of the belt and help you isolate the problem

What could also be happening is that your batteries were really low. They would have enough charge to start the boat but they were putting such a load on the alternator it would cause the belt to slip. I had that happen several times after sitting at a sand bar ect. I have since fixed this with a different battery and charger setup this year. Try isolating the low battery and just use one to start and see if it goes away.

loose belt

Water pump impeller is locked up... bet the pulley is not turning... if the motor rotates backwards just a tad when you shut it off and the impeller blades face the wrong direction and get jammed.. It will lock up the water pump.... time for a new impeller.. seen his a few times before.. more on the plastic housing pumps..

^Agree with the two above. I've had that happen before also. First try tightening the belt. But soon, replace the impeller. I'm almost certain Charlie Zulu has it called right.