Ruined two belts and two weekends on my 1995 supersport GT-40

[crentist]

I only know the abosolute basics when it comes to motors so please be gentle.
Before I took the boat out this year I noticed my existing belt on the alternator was hanging by a thread. It said 3L390 on the belt and was GREEN, so I found a similar belt at a hardware store but it was BLACK. I couldn't get the bleeping thing on! it was too small even after removing both bolts. So I bought 3L400 which seemed to be the right size. Well anyway I had to call it quits within 2 hours the last 2 times out as the belts starts smoking and basically getting destroyed. While on the lake, I would tighten the tension because I thought maybe these belts couldn't handle the high heat.

Are my belts not strong enough or heat resistant enough?? what belt type, brand and size should I be using??

Is my alternator going bad? It did seem pretty hot, so to retighten the belt I had to use a folded up damp towel on the alternator. the voltage gauge would be around 13 then dip to 12 when the belts were failing. If I need a new alternator what should I get? There is 3 pulleys total, what is connected to the other pulley? could that be my problem?

Very frustrated! and would rather not bring it in and loose another weekend, but maybe that's my best bet.

[crentist]

Hey guys the planetnautique search wasn't working but I was able to search the site though google and found some good info. I have a feeling the alternator is going bad since it is so hot? I am going to try and see if it spins freely? in the morning.... Does anyone know how free it should spin or feel?

Is an alternator something I should be able to tackle?

[shag]

There are a few things here. First of all, you must use the same size belt. You should be able to loosen your alternator enough to slide and allow you to put the belt on and then tighten.
You need to be sure there is not a reason the belt is wearing. Alignment issues between the pulleys of engine driven components and even a bad, or going bad alternator will cause a belt to wear. Even not having the correct tension will wear a belt. A alternator pulley should spin feely with no 'rough' spots. And yes, I have seen an older alternator bracket that was tweaked enough to make it out of line with the crank pulley. I always use PCM belts and have never had an issue with them, that said, I am sure there is an aftermarket belt of the same size and shape that would suffice.

[crentist]

Thanks for the response!
I checked the alternator out this morning and seemed to move freely. Maybe just the slightest tick/grind but overall pretty smooth.

To be safe I ordered a new stock alternator from nautique parts as well as belts. I debated getting the upgraded 100 amp? Alternator but not sure that I even needed it. I have one amp and installing 2 tsunami 800 pumps because I'm sick of filling bags. I've never noticed a drop in power so I think I'll be ok. Is it best for the alternator to fill and drain tanks with the motor running?

After I install the alternator what's the best way to check the alignment. Run and watch the belt?




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[shag]

Yes watching in line is one way. I would bet once you get a new alt and the exact belts... I would've gone with the upgraded alt but you might not have the higher amp breaker needed for it. Yes, I always would run the engine while pumping/filling, that's just me.