2000 225 EFI breaking Alternator belts

[cape cod basser]

( OT162159 ) Had a belt let go while at the Northern Rally so replaced it when I got home without issue. Havent used the boat since August so was going through it today and found the belt broke again. Couldn't have been more than six trips on the new belt so not sure what is going on. Alternator pully had a little rust but not much. I sanded it off to clean it up, but have had to change belts once in the years I have had the motor and now two in two months?

Also, The belt came apart in a bunch of pieces and the flywheel must have rubbed on the broken belt creating a bunch of black dust under the cover. Now I'm concerned about how much dust got into the intake or if any pieces got sucked in as well?
Looked to take the intake off today but everything is bolted to it, (fuel system, Fuel filter, etc), so I was not getting into trying it without having more time to dedicate to it. Not sure if I should even worry about taking it apart. Opinions?

( I am working out of town six days a week and only getting home for Sundays. Some of you may have seen the gas explosions in Lawrence MA. back in September, I work for the Gas Company that runs that district and we are rebuilding the entire system so my season ended the day that happened).

[EuropeanAM]

If you would, please take a moment to review the Announcements at the top of the Forum, and provide the Required Info with your post. Thanks!

Need to chase down all of that debris- I would recommend inspecting the reeds OFF the engine, and cleaning out any belt debris from the intake/reeds.

OEM belt would be my recommendation- it takes a real beating. Any pitting in the pulley will result in substantial (and premature) belt wear.

Proper belt tension (as stated in the Service Manual) is critical. If the belt is too loose, or too tight, it will wear RAPIDLY.

Hope this helps!

[cape cod basser]

So My Serial # is OT162159
I had the entire fuel system gone through . Injectors sent out, Cleaned & flow tested. All components on the front of the motor gone through. ( not by me, a certified Tech and engine builder).
He looked over the pulley and flywheel and only found the rusty surface I mentioned above. He removed the pulley from the Alternator and had it powder coated to smooth it out. Installed a new belt and set tension to specs.
I ran it a few times and checked it after each trip without issue.
I finally finished using the boat and pulled the motor cover to do some maintenance to put it away for the winter and found another broken belt..
The alternator shaft and bearing is tight, can't move the pulley at all in any direction which would tell me a bearing is bad.
Not sure what else to do at this point other than change the Alternator?
where is a good place to call for an Alternator?

Any advise? Has anyone else had a similar problem?

Thanks.

[Savage]

Take your alternator to a AUTOMOTIVE Alternator repair shop.

[EuropeanAM]

The belt you installed- was that OEM, or ? There is honestly a big difference in that most automotive belts aren't intended for 5500 RPM + operation.

How does that pulley look NOW? I've seen this a number of times and in the end had to replace the pulley (sometimes you can get a local alternator shop to replace it for you).

[cape cod basser]

I always use OEM so yes the belt was. Honestly the pulley LOOKS fine. The belt definitely looks narrower like it was binding on the edge somehow. I need to buy a new one again and mount it so I can put a straight edge on it to check how it is sitting.
Honestly there are a couple Mechanics I know scratching their heads over this one...

[JINXBASS]

I don't know if it has the same setup as a 250 pro xs but I had the same problem and it was the stud holding the tensioner. Without k owing g it was suppose to be flush with the top of the pulley it did not look out of place to me. So I took it to my mechanic and because the stud backed out some it caused the pulley to ride a little higher and in turn would allow part of the belt to ride off the pulley thus slowly tearing it to thread. Just thought I would throw that out there. Hope this is your issue due to being a simple fix.

[EuropeanAM]

I always use OEM so yes the belt was. Honestly the pulley LOOKS fine. The belt definitely looks narrower like it was binding on the edge somehow. I need to buy a new one again and mount it so I can put a straight edge on it to check how it is sitting.
Honestly there are a couple Mechanics I know scratching their heads over this one...

It's definitely different (not at all like the ProXS mentioned above).

One thing I can tell you- the 225/250/300 will turn a belt into fine powder in a BIG hurry if there is the slightest abnormality in the pulley, tension isn't right, or belt isn't high-quality. Not saying which one is the case... but something is causing it.

If you set a new belt into the groove of the alternator pulley, how deep does it seat?

[cape cod basser]

This sentence in red from the OP says it all...…"The alternator shaft and bearing is tight, can't move the pulley at all in any direction "

Not talking about the normal spin for the alternator, Just saying if you try to see if the top bearing on the alternator is bad the pulley would rock the slightest bit. Alternator is still working fine and no indication of worn shaft, bearing or pulley.

[EuropeanAM]

Gotcha, Pat. As Savage noted, that could have been interpreted differently.

Still recommend checking how deep a NEW OEM belt sits... and you might want to consider seeing if a local Alternator Shop can get you a new pulley (strongly recommend painting it and full-curing the paint before use).

[Savage]

Not talking about the normal spin for the alternator, Just saying if you try to see if the top bearing on the alternator is bad the pulley would rock the slightest bit. Alternator is still working fine and no indication of worn shaft, bearing or pulley.

I see.

[cape cod basser]

Gotcha, Pat. As Savage noted, that could have been interpreted differently.

Still recommend checking how deep a NEW OEM belt sits... and you might want to consider seeing if a local Alternator Shop can get you a new pulley (strongly recommend painting it and full-curing the paint before use).

Will do Don, will report back once I get one.

[Melton Jason]

You should be able to find a local authorized Denso repair facility and have them order a replacement pulley for it. It was only $40 from my local guy for the part and him to install it. .

[Knuckle]

I have a brand new alternator with only about 2 hours on it if you are interested?

[lpugh]

Gotcha, Pat. As Savage noted, that could have been interpreted differently.

Still recommend checking how deep a NEW OEM belt sits... and you might want to consider seeing if a local Alternator Shop can get you a new pulley (strongly recommend painting it and full-curing the paint before use).

When you check this you need to verify that the belt does not bottom out in the pully, meaning the narrow part of the v should be about 1/8 in from the bottom in the pully, this is critical. Most fail to check this

[EuropeanAM]

Also make sure the wide part of the "V" isn't seated below the outside diameter of the pulled. A belt that sits too deep in the pulley will tend to "bite" down into the groove and then be yanked back out (entering/exiting as pulley spins), causing substantially more wear.

[cape cod basser]

Also make sure the wide part of the "V" isn't seated below the outside diameter of the pulled. A belt that sits too deep in the pulley will tend to "bite" down into the groove and then be yanked back out (entering/exiting as pulley spins), causing substantially more wear.

This makes a TON of sense. Will check it out once I get a belt.
Thanks !!

[cape cod basser]

I have a brand new alternator with only about 2 hours on it if you are interested?

What is it off of?

[Knuckle]

What is it off of?

2000 mercury 225 efi and a new belt

[cape cod basser]

2000 mercury 225 efi and a new belt

PM me a price. Sounds like what I need and I may need to keep a spare belt around..