Corroded alternator and engine pullies

[47401]

We have a beta 43 with two alternators. We are not cc. Boat spends most of the time in the marina. Noticed from when we purchased 6 years ago a lot of rubber around the back of the engine in the area of the smaller starter battery alternator.

Never had a belt failure but they are getting worn away because the 3 pulled are all corroded and this causes the belts to wear. As the v belt gets thinner it goes deeper into the V and eventually we run out of adjustment.

All 3 pullies are affected lower engine, upper engine and alternator.

Any suggestions on what to do?

We could just keep changing the belts but that is a pain and expensive if we use the Beta part. Changing the pully wheels would be another way but it seems to me it would occur again.

Martin

 

[matty40s]

Belts are like batteries, you have to replace them.

Changing the pulleys will be far more expensive, achieve nothing, and possibly negate any warranty you have. You could clean up the corrosion with a fine wire wool or wet and dry paper, although stopping them corroding by keeping water/damp out of the engine bay would be preferable.

 

[nicknorman]

21 minutes ago, 47401 said:

We have a beta 43 with two alternators. We are not cc. Boat spends most of the time in the marina. Noticed from when we purchased 6 years ago a lot of rubber around the back of the engine in the area of the smaller starter battery alternator.

Never had a belt failure but they are getting worn away because the 3 pulled are all corroded and this causes the belts to wear. As the v belt gets thinner it goes deeper into the V and eventually we run out of adjustment.

All 3 pullies are affected lower engine, upper engine and alternator.

Any suggestions on what to do?

We could just keep changing the belts but that is a pain and expensive if we use the Beta part. Changing the pully wheels would be another way but it seems to me it would occur again.

Martin

 

We have a Beta 43. 12 years old now. No problems with the starter battery alternator belt or pulleys. I have replaced the belt twice in about 4000 engine hrs. The starter battery alternator should be very lightly loaded unless there has been some electrical modification that loads the alternator more than standard. Starting an engine uses less than 1Ah and that gets replaced in a couple of minutes, the rest of the time the alternator is just idling. Which is why our belt doesn’t make black dust.

 

I would suggest checking the alignment of the pulleys. If the pulleys are not exactly aligned, this causes belt wear, lots of black dust etc. Put a straight edge along the side of the pulley and check its pointing at the side of the other pulleys. Also check for any axial play in the pulleys. If everything is fine, I guess you will have to replace or overhaul the pulleys, but I’m more inclined to suspect misalignment.

Edited April 2, 2023 by nicknorman

[David Mack]

V belts are available from a number of suppliers locally or online.

When replacing the belts I would give the inside faces of the pulleys a good scrape and maybe run over them with sandpaper.

[MtB]

1 hour ago, 47401 said:

the 3 pulled are all corroded and this causes the belts to wear.

 

This is odd. The pulleys on my own boats don't corrode to the extent the vee belts wear excessively even if left unused for long periods. Is your engine bay particularly damp or wet perhaps? 

 

I'd expect any fine surface rust to wear off in five or ten minutes of engine running, and certainly without causing rubber dust. As Nick suggests, it sounds to me as though one of your pulleys is way out of alignment with the other two.

 

 

[Momac]

What's causing the corrosion? 

[MtB]

17 minutes ago, MartynG said:

What's causing the corrosion? 

 

Its a good question. My pulleys don't corrode but then my engines are in proper engine rooms. My guess is this will be in a cruiser stern with leaky deck boards.

 

 

[Tracy D'arth]

If the alternator has a single foot mount at the pivot mounting it is not unusual for them to be miles out of alignment with the other pulleys due to the hole becoming elongated. That is the usual cause of excessive belt wear.

[Momac]

16 minutes ago, MtB said:

 

 a cruiser stern with leaky deck boards.

 

 

Perhaps that type of fault can be corrected.

 

 

[MtB]

Just now, MartynG said:

Perhaps that type of fault can be corrected.

 

 

 

It can, but rust on the surface of the pulleys won't be the cause of rubber being ripped off the vee belt in such quantities to cause premature wear or the visible deposits of rubber dust described by the OP.

 

 

[cuthound]

My Beta 43 has two alternators. When we got the boat it was almost impossible to adjust the starter battery alternator belt tight enough. I suspect the belt was the wrong one. I replaced it with a shorter cogged belt and after its initial stretch after fitting, have not had to adjust it since.

[Iain_S]

I've seen a couple of Betas where the cabin alternator pulley is out of line.

 

Just a thought: how's the water pump (upper pulley on engine)? If that's worn and leaking slightly, it could explain the rusty pulleys and the belt alignment problem, if that is on the engine alternator.

[Pie Eater]

I used to change the belts every 400 hours along with the air and fuel filters.

 

Nothing worse than a belt snapping just as you set off.

[47401]

9 hours ago, cuthound said:

My Beta 43 has two alternators. When we got the boat it was almost impossible to adjust the starter battery alternator belt tight enough. I suspect the belt was the wrong one. I replaced it with a shorter cogged belt and after its initial stretch after fitting, have not had to adjust it since.

Thanks for all your replies.

 

This sounds like the problem I am experiencing exactly. I have already tried a couple of slightly shorter belts V type 13x 8 mm. Unfortunately my slightly shorter was too short but I could get a few shorter belts before you reach the cost of the Beta belt.

 

It is a semi trad stern with separate engine bay. No water coming in. No oil laying under the engine. Does get a bit of condensation from time to time. It is not used regularly at the moment.

 

I'll check the alignment again and use some emery paper on the pullies. I'll look for another belt. I am sure the outside length of the Beta belt is around 42.5" but I will check that again. 

 

Ta everyone M

[jonathanA]

Yes I had an alternator that used to chew multi rib belts. Eventually checked the alignment and it was out by a very small amount. After advice on here I cleaned all the grooves on all the pulleys too.  Had no more problems but just change the belt at every service as a matter of course. 

 

To be fair I don't use OEM belts but cheaper alternatives.