Beta belt dust?

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silverdawn

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Hi All,In my present boat I have a Beta 20Hp engine year 1998 also my previous boat had the same engine year 2001, both created large amounts of black belt dust, speaking to Beta they advised to update the belt system with their conversion kit which comprises of new pully wheels and a wider toothed belt ,these are fitted to engines from about 2005 onwards.
The kit cost about £150.00 which I dont have spare, however on looking at the Beta website
they suggest that lack of ventilation to the engine compartment ie less than 200cm2 could cause black belt dust due to excessive heat around the alternator area.
The engine front access cover is in the saloon a factory finished fibre glass cover which is insulated and purposed made to deaden noise and prevent fumes /flames from entering the cabin. the only way I can introduce ventilation around the alternator area is by drilling two 100cm2 circular holes and covering them with metal hit and miss vents which could be opened when running the engine.
Other than the belt dust the engine run perfectly,So do I drill my perfect engine cover to (maybe) get rid of the belt dust or do I leave well alone and just change the belts more frequently.
 
We have the same problem. Unfortunatly the black dust problem can't be solved as easily as ventilation. My engine is sat under the cockpit which has a space running back about 5 ft behind the engine and out through the cockpit lockers. I doubt the ventilation problem is the key as ours is very well ventilated and has the same problem.

The problem has been reduced slightly by changing the belt from the Beta recommend, to an agricultural machinery belt of the same dimensions. This seems to have helped things a little.

We are still toying with the idea of changing to the flat belt but I am still happy to give it a clean out each winter as long as it keeps working.

The engine code for these engines is BD722 IIRC.
 
Shanty has a 13.5hp Beta dating from 1998. Originally, it had the single vee belt drive, which created a lot of black dust. A few years back I converted it to polyvee drive (using the Beta Marine kit). Since then , no dust problems.

FWIW, I suspect the original belt setup may have been a bit under-spec'd for the job.

A worthwhile change.
 
silverdawn said:
Hi All,In my present boat I have a Beta 20Hp engine year 1998 also my previous boat had the same engine year 2001, both created large amounts of black belt dust, speaking to Beta they advised to update the belt system with their conversion kit which comprises of new pully wheels and a wider toothed belt ,these are fitted to engines from about 2005 onwards.
Click to expand...
I had an identical problem with a Yanmar 2GM20 in my last boat. A new belt went swiftly the same with black dust over everything in the vicinity.

When I mentioned the problem to a mechanically-knowledgeable friend he started the engine without the belt attached, held a folded strip of emery cloth in the vee of the the drive pulley until the surface was clean and polished, then very lightly greased it. From then on I occasionally repeated the procedure and never had a repeat of the black belt dust. In my case the problem was an invisible film of rust that had formed on the inside of the pulley wheel. Perhaps yours is a similar case.

Edit: the rust was the result of microscopic pitting of the wheel and did not itself cause the problem - the polishing did the trick by smoothing off the pitting, which did chew the dust off the belt.
 
Last edited:
silverdawn said:
Hi All,In my present boat I have a Beta 20Hp engine year 1998 also my previous boat had the same engine year 2001, both created large amounts of black belt dust, speaking to Beta they advised to update the belt system with their conversion kit which comprises of new pully wheels and a wider toothed belt ,these are fitted to engines from about 2005 onwards.
The kit cost about £150.00 which I dont have spare, however on looking at the Beta website
they suggest that lack of ventilation to the engine compartment ie less than 200cm2 could cause black belt dust due to excessive heat around the alternator area.
The engine front access cover is in the saloon a factory finished fibre glass cover which is insulated and purposed made to deaden noise and prevent fumes /flames from entering the cabin. the only way I can introduce ventilation around the alternator area is by drilling two 100cm2 circular holes and covering them with metal hit and miss vents which could be opened when running the engine.
Other than the belt dust the engine run perfectly,So do I drill my perfect engine cover to (maybe) get rid of the belt dust or do I leave well alone and just change the belts more frequently.
Click to expand...

After suffering exactly the same problems with the Yanmars on current (& 2x previous) boats. I found that the dust is caused by belt wear caused by the belt being too 'fat' to sit right down into the pulley wheel groove.

I changed the expensive manufacturer's belt for a toothed Gates belt from a local motor factor. As this will actually sit nicely into the bottom of the pulley wheel groove, it can be smaller diameter than the standard belt.

Cost: about £3. Dust: gone.:)
 
rudolph_hart said:
After suffering exactly the same problems with the Yanmars on current (& 2x previous) boats. I found that the dust is caused by belt wear caused by the belt being too 'fat' to sit right down into the pulley wheel groove.

I changed the expensive manufacturer's belt for a toothed Gates belt from a local motor factor. As this will actually sit nicely into the bottom of the pulley wheel groove, it can be smaller diameter than the standard belt.

Cost: about £3. Dust: gone.:)
Click to expand...

Interesting, as it worked, I've no problem with your solution. I'd observe though that the belt should NOT sit in the bottom of the pulley, it's called a 'V' belt because it grips the side cheeks.

Nick (with dusty Yanmar belt)...
 
Barnac1e said:
I had an identical problem with a Yanmar 2GM20 in my last boat. A new belt went swiftly the same with black dust over everything in the vicinity.

When I mentioned the problem to a mechanically-knowledgeable friend he started the engine without the belt attached, held a folded strip of emery cloth in the vee of the the drive pulley until the surface was clean and polished, then very lightly greased it. From then on I occasionally repeated the procedure and never had a repeat of the black belt dust. In my case the problem was an invisible film of rust that had formed on the inside of the pulley wheel. Perhaps yours is a similar case.

Edit: the rust was the result of microscopic pitting of the wheel and did not itself cause the problem - the polishing did the trick by smoothing off the pitting, which did chew the dust off the belt.
Click to expand...
Hi Barncac1e, Interesting idea and works for you I will give it a try but must admit Iam not very optimistic, it seems that the older Beta engines suffer from belt dust problems, other owners I have spoken to also comment on the problem.
I was interested to see if anyone had overcome this problem by increasing the ventilation into the engine compartment near to the alternator . thanks for your comments.
 
I had the same problem with a nanni 20hp(same as your beta). I found that the alternator mounting holes had slightly elongated and so the alternator wasn't sitting square. Found a slightly bigger bolt and that improved things bigtime. I still have some belt wear but nothing like it was before. I'm tempted to drill out the holes and insert some bushes to make it perfect. Job no. 182! I just make sure I have a spare belt onboard the the tools to do a change.
 
Volvo D1-30B

I have had this problem, but only since I replaced the original equipment belt with a Volvo replacement. My engine compartment is well ventilated. After much adjusting of the belt tension to no effect, I have re-fitted the old worn belt and the problem has almost disappeared again. I intend trying to find a non original belt during the winter and trying that.
May I say how pleased I am to find that I am not alone in having this problem.
CJ
 
My 1995 Volvo MD2030 did a belt every week due to misalignment. A 1 pence washer between the alternator and the bracket solved the problem.
Gerard
 
We have the belt dust 'problem' on our Beta 13.5hp. More of a problem is the belt has to be tightened too often for convenience (though I've come to be able to do it very quickly now!).

A Beta accredited engineer told me the belt on the small Betas had always been too small and given these problems, that Beta were aware of it, and he was surprised that they hadn't upgraded it. (An earlier poster said they did in 2005, our engine is 2004/5.)

We bought the multi-vee belt conversion a while ago, though were a bit surprised how expensive it was, but have yet to fit it (for unrelated reasons).

Have to say that other than this we are very pleased with the engine.
 
You can add my Beta 20hp to the list also. Also the belt occasionally squeals when the battery is a bit flat and there is load on the alternator. The engine is excellent, however, and we really steam along
 
pmagowan said:
You can add my Beta 20hp to the list also. Also the belt occasionally squeals when the battery is a bit flat and there is load on the alternator. The engine is excellent, however, and we really steam along
Click to expand...

Unfortunatly that means the belt has worn too much!

Replacement will cure that, along with the problem with the rev counter not showing enough revs ;)
 
We installed a Beta 20 about five years ago and just last week I thought that there was rather a lot of dust around the frontof the engine. My son in law suggested that the belt needed tightening, so we did that and I will watch to see if there is any change over the next few weeks, but it is interesting to hear that we are not alone.
 
Ceejay said:
I have had this problem, but only since I replaced the original equipment belt with a Volvo replacement. My engine compartment is well ventilated. After much adjusting of the belt tension to no effect, I have re-fitted the old worn belt and the problem has almost disappeared again. I intend trying to find a non original belt during the winter and trying that.
May I say how pleased I am to find that I am not alone in having this problem.
CJ
Click to expand...

I was told once by an electrician/engineer that the black dust is due to overheating of the belt due to friction caused by slippage through not sitting properly in the groove of the pulley either due to the incompatible profile of the belt, or slackness in the tension. In this occasion, re tensioning to the recommended settings cured the problem. Anyway, another temporary cure is to use ROCOL Belt dressing spray. It stops dust and squeel immediately.
 
Dougie_the_Mate said:
We installed a Beta 20 about five years ago and just last week I thought that there was rather a lot of dust around the frontof the engine. My son in law suggested that the belt needed tightening, so we did that and I will watch to see if there is any change over the next few weeks, but it is interesting to hear that we are not alone.
Click to expand...

I had quite a lot of dust on my Beta and found the belt to be a bit loose.I tightened it up and there was not dust when I motored from Mazagon to Tavira,about 40 miles.Let's see how it goes from now on.
 
I keep a spare belt. I might consider the retrofit but is a bit expensive considering the current setup works and only slips when in high revs with low battery power. Changing the belt doesn't seam to make much difference and I have adjusted tension. I don't mind the dust
 
My much larger engine (Beta 2203) used to eat conventional belts, partly due to misalignment, but also because the alternator pulleys were small.

Switching to toothed belts cured all of the shredding and most of the black dust.

Toothed belts are not much more than a standard v belt and I hadn't needed to change the belts in two years.

Supplies available from BearingBoys (do a google), whose postage charges are very reasonable.

For other reasons I've recently had to change to poly-V belts and pulleys and to date I'm NOT impressed, but that may be due to a dodgy installation. However, my alternators are huge (140 amps at 12V), perhaps I'm expecting too much....
 
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