I just aquired a 1991 Scarab Excel 21ft with a 454. I got it from a friend who bought it for her boyfrined but they broke up. He used it for a month then it sat for 2 weeks before I got it. She got the boat back and I bought it. It was missing the alternator when I got it also. I was told it went bad and he had it at his house. Well I tried to fire it up without the alternator just to hear it run for a second but it wont start. Will it not start because it doesnt have the alternator?? I know you can do this with a car but not a boat? Also what is the part number for the alternator I need? It has 4 wires going to it. Thanks!

It should be able to start without the alternator.
Get the old one back.

I tried, thats a lost cause. I am gonna have to just buy a new one. If it doesnt start after I put the alternator on I am going to bring it to a marine mechanic.

Punch the serial # in at mercuriser.com parts express and you can get a parts list and pics , prices and local dealers.

Would you give a perfectly good boat back to your ex ? ?

Thast what I said too!
He isnt that smart. This guy was a big dummy from what I understand. He gave it back to her but was thinking that she was just mad and would be over it in a few days. I came down and got the boat right after she got it back and he called her the next day and was like where the heck is the boat!! She was like sorry, I sold it and it went out of state.
I have dedicated this weekend to getting it running. I will let you guys know what I find.

Well I got it running today and it runs great! I cant wait to get it in the water.

Did you use "ear muffs" on the lower unit to feed the engine water?

Of course! Now I need to get the prop fixed and install an alternator.

Good. Just checking.