New alternator and noisy belt

Installed a new alternator and took it out to the lake yesterday. Initially the belt would make a funny noise when revving the engine but after a while it would only squeal when starting up for a few seconds.

On my boat there is no way to tighten the belt (that I can see), so the only thing I can figure is that the pulley on the new alt. is slightly smaller than the old one.

Do I need to try and find a new belt that is a little smaller or is there something else that I am missing here ?

belt has to be adjustable. there should be a bracket that connects from the alt to the front of the intake. you could adjust from either side. or this one of those serpentine jobs? either way, I bet it adjustable. sounds a little loose.

My alternator bracket does not have any adjustment on it, just two holes for the bolts.

This is on a 1996 VLX and it is a v-belt.

few things, when you put a new alternator on always replace the belt, if the pulley looks different, change the pulley with the original one. with a new alternator and belt it shouldn’t make a squeak, the alternator will have holes for mounting, the adjustment is on the bracket, unless you have something else on the same belt, then the adjustment will be on that.

The belt still looks like new but I am going to replace it anyways, the pulleys look the same but I am thinking it maybe has a slightly smaller diameter than the original. I upgraded from a 60amp to a 105 amp.

I promise you guys that there is no adjustment on my alt. bracket. It is just a solid bracket with two holes for mounting the alternator.

Clint, one of the pulleys or an idler on the belt has to adjust. On a Mercruiser and a PCM in a Centurion there is a seperate belt tension idler.

The current year model Malibu engines pictured on the Indmar website all use the alternator for the adjustment. The Mastercraft and Skiers Choice engines all show the same alternator adjsutment. The sliding bracket is on the bottom of the alternator. www.indmar.com Your older model may be different.

Clint I know what you are talking about. I've looked at my Mercruiser Mag 350 in my Elite V and I have not seen any adjustment. I've looked a couple times, but probably could look closer. There sure isn't anything very obvious. All my manual says is if the belt deflects more than a quarter inch at the longest distance between two pullies, see your Mercruiser dealer for adjustment. So there must be an adjustment somewhere but I haven't found it yet. I will do some more checking.

Figured it out today, took me really having to stick my head in there.

On my boat you do not adjust the alternator on the bracket, you adjust the bracket coming off the block. There are two bolts holding the bracket to the engine and at the bottom bolt is a very small groove in the bracket that allows for adjustment. Pretty hard to see it with the bolt and washer on there.

Tightened her up hooked up the fake-a-lake and all seems good now.

Cool Clint. Glad you got it figured out. I'll try and remember to look at mine. It must be the same as yours.