Alternator Belt Producing Excessive Black Dust

[utyak]

2010 Island Packet Estero (36.5'), with Yanmar 3JH4 E engine and factory installed Balmar 100 amp alternator. Alternator belt is producing significant amounts of black dust. Have had the belt re-tensioned then re-aligned with new mounting hardware by a diesel mechanic with a good reputation, under warranty. Still getting lots of black dust. I've been in touch with IP, the Yanmar distributor and Balmar trying to resolve this. The Balmar rep said the 1/2" V belt used in the installation was at it's maximum power transmission capability with the 100 amp alternator, and thought from the information I was giving him, it might be a problem with the alternator belt slipping, as a result of the alternator bracket slipping.

Anyone else out there with a similar set up seen this problem?

Thinking about trying the kit Balmar/Altmount sells with a wider, ribbed serpentine belt.

[sailorboy1]

What kind of output are you getting from the alternator? Hard to blame the loading if it isn't really cranking out amps.

If it putting too much out and you have a Balmar regulator you could use the belt load program to reduce the output some.

[model 10]

Same problem for the past 2 years. Belt life was really short also. I think we are coming close to the limit of a single belt with a 100amp alternator. For me it was finding a really good quality belt that fit correctly and keeping the tension correct. Some of these belts you buy are crap.

[JPA Cate]

If all you want to do is get rid of the symptom, and the belt is the correct length, try spraying belt grip on the belt with the engine running, use something to block its getting all over everything else--a folded newspaper or a magazine will do.

Otherwise, you might be able to find a notched belt that is strong enough. You'll need a belt shop with a good selection. Take off the existing belt and take it with you.

Someone may tell you you need to change pulley size, something sometimes easier said than done.

Finally, if the belt adjustor is all the way bottomed out (nothing more to tighten), maybe you're due for yet another new belt, a wee bit shorter.

If the belt has been squealing, while the engine is running, it has been slipping. The black dust is rubber off the belt.

Ann

[Stu Jackson]

It is not aligned properly. Fix the alignment before you use belt grip, 'cuz that ain't gonna fix the real issue.

[Cheechako]

Every 100 amp alternator on a single belt I've had has done that If it had a high output regulator. I found the Dayco "Cog" belt the best and the Napa Greenstripe second best. With a normal external regulator no belt issues. If you have the Balmar regulator you could adjust it back a bit ...cant you? Unless your battery bank is huge you can only pump in max amps for a short time anyway...usually about 20 mins in general on my boats... after that your belt is fine.
for example: 100 amp output for 1/3 hours = 33 amp hours. 80 amp output for 1/3 hours =26.6 amp hours. Is it worth the trouble?

[Snore]

Utyak

How do you use the boat? How important is the full 100 Amps?

I have the Balmar smart regulator. Putting a jumper wire across two terminals reduces the alternator 50%. This eliminated my belt dust.

So if you have a lot of solar, or like me usually day sail, run the alternator at 50%. When doing a trip, when anchored, I remove the jumper and run 100 amps.

It is amazing how much "happier" the 24HP engine seems to sound when it it not turning the full 100 amps.

[Stu Jackson]

[QUOTE=Snore;1600842

I have the Balmar smart regulator. Putting a jumper wire across two terminals reduces the alternator 50%. This eliminated my belt dust. [/QUOTE]

Snore's right.

It's called

Small Engine Mode - discussion with link to the picture of the toggle switch: Alternator heat, Regulator Controls, Small Engine Mode

With a Balmar external regulator, you can also use Amp Manager.

RTFM.

[Bruce Beard]

We have the same engine and alternator. It is tough to know how much dust is normal but we do not get much. Yanmar belts are replaced annually after about 200-250 hours on our boat and they look new.
If you really want to know if the belt is mentioned properly spring for this tool made by OTC. It is pricey but I can promise it is money well spent. I'd wager that your belt is badly under mentioned but do not take my word for it. Beg, borrow or buy the tool, you will be surprised!

Amazon.com: OTC 6673 Universal Belt Tension Gauge: Automotive

[lancelot9898]

I've had good luck with the Gates Greenstripe 1/2 inch belt for my 75 amp Balmar(Model 91-75). Recently the alternator failed to charge the battery and after 24 years I guess it's time for replacement. The alternator is being refurbished and the regulator ARS-4 is being replaced with the ARS-5. The belt is doing fine still, but that too is being replaced.

[robert sailor]

100 amps is right at the max for a single belt...I'd be doing something to back it off a bit.

[GordMay]

Greetings and welcome aboard the CF, utyak.

[SimonV]

I too have a Belmar 100A alternator I have had the same belt for 3 years and just this month swapped it out for a new one. The adjuster had reached its limit and i was getting lots of black dust. New belt same as the old but I'm back with a 1.5" available adjustment. Also no black dust. I tighten so i can twist the belt 1/4 turn.

Sent from my GT-N7105T using Cruisers Sailing Forum mobile app

[a64pilot]

Originally Posted by utyak

Thinking about trying the kit Balmar/Altmount sells with a wider, ribbed serpentine belt.

This I believe is the best long term solution, if you want to keep 100 amps output on your alt. If your OK having less alt output turning it down will also fix the issue, but then why have a 100 amp alt?

[a64pilot]

I don't think this is a hikack, but has anybody used one of these?
Balmar Belt Buddy alternator tensioning device