Yanmar 2ym15 Burning belts

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steveeasy

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Hi,
Got a relatively new Yanmar 2ym15 that likes to munch through water pump and alternator belts. fair bit of dust and lucky if I get 40 hours out of them. Pulleys not overly rusty. Use genuine belts. both the water pump and alternator last about the same time. Not sure how they could be out of alignment. wondered if anyone else has found a similar problem.

Steveeasy
 
Mysterious. I have had belts that only did 100 hours , and some that did 1000. The good ones come from Fenner. Bearing services used to supply me, but then one day the brand changed along with durability see above. I expected to change them every year at about 1000 hours, but Fenner always looked good for another year.
 
When I was an engine builder, Gates were considered a good brand of belt. What sort of belt deflection measurement are you working with?
 
Try CRE belts(Cogged Raw Edge) belts of the same length and size, they transmit more hp than standard vee belts. Make sure they are tensioned correctly, Gates are a good make.
 
Thanks. The pulleys really dont have rust on. I do use genuine belts might try CRE belts then. given both wear fast , perhaps i should check alignment of the crank pulley with the other two.
Thanks
Steveeasy
 
steveeasy said:
Thanks. The pulleys really dont have rust on. I do use genuine belts might try CRE belts then. given both wear fast , perhaps i should check alignment of the crank pulley with the other two.
Thanks
Steveeasy
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I had similar problems with my Beta and was recommended to use a toothed belt in place of the v belt. Problem solved and that was 10 years ago!
 
Be sure not to over tighten the belts. Major source of water pump failure on YMs to be avoided. (The bearings are weak ).
 
Dont seam to ever had a problem before with any type of engine. Ive had loads of machinery. Im wondering now rather than an alignment issue, if it might de down to overtightening and perhaps distorting the position of the water pump pulley. its not up to much anyway. the alternator has good brackets but it does the same. Ill defiantly try different belts this time.
Steveeasy
 
Are you sure that the pulleys aren't rusty? The wearing belts make the corrosion look black, not rust coloured, and difficult to assess visually. Even fairly slight roughness is bad news for belts, I'd get the emery cloth out. Also, as you mention, check the alignment
 
When I uprated my engine alternator and batteries, the standard V-belt could no longer cope with the load and wore rapidly. Changing to a CRE belt cured the problem. No idea why both your belts show increased wear - surely rust, tension, and alignment are the only significant factors.
 
fisherman said:
Had a boat laid up from March to august then sold it. I ran it for two hours before they took it, six hours later mid channel, belts failed.
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Same for me. The boat had had little use for a while, but the impeller seemed fine. Sold her, then got a call from the new owner. The impeller had shredded itself going down the harbour. Fortunately, I was able to tell him where to find the spare and all was well.
 
In my case they were between Falmouth and Guernsey, 123nm, 25ft open boat. They didn't have the stomach at midnight for hanging upside down replacing the belts, and not familiar with procedure. They put string round, enough to run the water pump. At daybreak stopped the engine, did the change, no batteries, after nav lights all night. Forunately there was a dual system, switchover and off again.
Another case for having link belt backup, which I carried since.
When my belts failed they damaged the alternator fan, the vibration kept loosening the alternator adjustment, slow trip home. You never know.....
 
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