I installed a Balmar 90-75 alternator on my Beneteau 361 with a Westerbeke 30B-3 27hp diesel. I continue to have problems with engine belts wearing out, slipping and shedding black particles all over the engine. Any suggestions would be appreciated.
Belt problems with Balmar alternator
- Thread starter GWG
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1. Look carefully at all the sheeves (crankcase, water pump, and alternator) pitting or surface roughness where the belts contact the sheeves. Especially the waterpump sheeve made from 'pressed steel' is very subject to rusting/pitting when the engine isnt run for long periods. Cast iron and cast/machined steel sheaves can be 'dressed' by a machinist back to 'smooth'; with pressed steel its usually cheaper and faster to just replace them.
If a sheeve is 'worn out', the smallest part of the bottom-vee will be coming in contact with bottom of the vee groove on the sheeve.
2. If the alternator sheeve is not 'square' with the other sheeves, the belt will ride higher on one side of the sheeve .... check the alignment of the alternator sheeve with the other 2.
3. If all the 'mechanicals' (above) are OK AND your alternator is EXTERNALLY REGULATED (by a 'smart' regulator), then you can adjust how FAST the alternator applies electrical load hence pulley/belt load. On most 'smart' regulators you can easily change the programming of how 'fast' the alternator 'reacts' to changing loads and rpms. With a 'smart' regulator you can easily 'derate' an alternator slightly until the belt no longer slips, etc. .... this assumes that all the 'mechanicals' are OK, first.
A 90 amp alternator at max. electrical load is 'just about' at the limit of too much load for a 1/2" vee belt.
4. Are you using a BELT TENSION gage when adjusting? ... no overtightening (stretching), no undertightening. Such gages/tools are CHEAP ... from NAPA, etc.
5. Many of the 'cheapy' vee belts being imported (even by OEMs) are crap. My choice for all vee belts in important service is GATES premium belts - longer lasting, less stretch over time, stay 'softer longer', etc. etc. etc.
If a sheeve is 'worn out', the smallest part of the bottom-vee will be coming in contact with bottom of the vee groove on the sheeve.
2. If the alternator sheeve is not 'square' with the other sheeves, the belt will ride higher on one side of the sheeve .... check the alignment of the alternator sheeve with the other 2.
3. If all the 'mechanicals' (above) are OK AND your alternator is EXTERNALLY REGULATED (by a 'smart' regulator), then you can adjust how FAST the alternator applies electrical load hence pulley/belt load. On most 'smart' regulators you can easily change the programming of how 'fast' the alternator 'reacts' to changing loads and rpms. With a 'smart' regulator you can easily 'derate' an alternator slightly until the belt no longer slips, etc. .... this assumes that all the 'mechanicals' are OK, first.
A 90 amp alternator at max. electrical load is 'just about' at the limit of too much load for a 1/2" vee belt.
4. Are you using a BELT TENSION gage when adjusting? ... no overtightening (stretching), no undertightening. Such gages/tools are CHEAP ... from NAPA, etc.
5. Many of the 'cheapy' vee belts being imported (even by OEMs) are crap. My choice for all vee belts in important service is GATES premium belts - longer lasting, less stretch over time, stay 'softer longer', etc. etc. etc.
All of the suggestions Rich H has made are good ones. I had the exact same issue you describe when I purchased my current boat from the previous owner. It took me about 4 tries before I found the "right" belt that has since lasted for several hundred engine hours. In my case the "right" belt is a Napa model of the appropriate size.
Good Luck.
Good Luck.
Out-of-line sheaves in the number 1 belt killer. Lay a straight-edge across them, or even sight the run as the engine idles. You may have to install spacers or washers or maybe even just turn the alternator sheave over.
Balmar recommends Top Cog from Dayco and Green something form gates. The Balmar sheaves are measured in fractions of inches and the Yanmar are in MM and that’s the problem. I just got a Dayco Top Cog for about $11 at a local auto part store, a lot less than a Yanmar belt!!!!!
I was able to increase the belt size (an 8th or a 16th, can't remember) using the same pulleys when I put my Balmar 75 on. I chose to go with a slotted racing belt from auto parts because Calder said the slots dissapate heat better. Regardless, the one belt does a great job.
Had the same problem on my Balmar 100 amp on a Volvo 28hp. Tried the higher quality slotted belts and reprogrammed the ramp up time and adjusted often with some success, but still more than average belt dusting. I installed a larger diameter pully for the Balmar and it solved the problems. It is a machined pully from Balmar, not the stamped metal type on auto's.
If you're replacing an alternator (eg upgrading to a Balmar), the sheave on the new alternator should agree with the rest of the engine. The simplest way to do this is to take the sheave off of the stock alternator and install it on the new one, if possible.
We put a new Yanmar diesel onto a customer's boat. Customer wanted to continue to use their own externally-regulated alternator, so we obtained a Yanmar-compatible sheave to use on that alternator so that the stock Yanmar belt would fit.
And seconding the good advice from Rich and Larry.
We put a new Yanmar diesel onto a customer's boat. Customer wanted to continue to use their own externally-regulated alternator, so we obtained a Yanmar-compatible sheave to use on that alternator so that the stock Yanmar belt would fit.
And seconding the good advice from Rich and Larry.
A bit of belt experience.
In commissioning my 2007 373 Beneteau with a 40ho Yanmar 3JH4E, I installed a 125 amp Amptech S125 alternator along with a Balmar ARS-5-H programmable regulator. The Yanmar and the alternator both had 1/2" (=SPA 12.7 MM) sheaves. I knew the single 1/2 sheave was pushing the limits on a 1/2" belt and have limited the max loading to about 100 then about 90 amps.
The original Yanmar belt was too small and I had to switch to a 44" belt, and consistent with a Nigel Calder article tried a Gates Green belt. I had problems with rapid deterioration and slippage which were minimized by: 1, lowering the max loading, 2, correcting over tightening of the belt, and finally switching to a standard NAPA cogged belt. This was the critical change.
The properly adjusted cogged belt has now been in place for a full season with limited dusting. Getting the right tension is a challenge as a loose belt will hit the water pump frame.
The green belts dusted and deteriorated terribly, especially the edge covering over the "V" edges.
In commissioning my 2007 373 Beneteau with a 40ho Yanmar 3JH4E, I installed a 125 amp Amptech S125 alternator along with a Balmar ARS-5-H programmable regulator. The Yanmar and the alternator both had 1/2" (=SPA 12.7 MM) sheaves. I knew the single 1/2 sheave was pushing the limits on a 1/2" belt and have limited the max loading to about 100 then about 90 amps.
The original Yanmar belt was too small and I had to switch to a 44" belt, and consistent with a Nigel Calder article tried a Gates Green belt. I had problems with rapid deterioration and slippage which were minimized by: 1, lowering the max loading, 2, correcting over tightening of the belt, and finally switching to a standard NAPA cogged belt. This was the critical change.
The properly adjusted cogged belt has now been in place for a full season with limited dusting. Getting the right tension is a challenge as a loose belt will hit the water pump frame.
The green belts dusted and deteriorated terribly, especially the edge covering over the "V" edges.
Cogged Belt Experience
While I had not had the experience you did, my Balmar belt deteriorated; started delaminating. I was in Catalina, and could only find a cogged Gates belt to match. However, the dusting I used to experience disappeared and 500 hours later, the belt looks great. FWIW
While I had not had the experience you did, my Balmar belt deteriorated; started delaminating. I was in Catalina, and could only find a cogged Gates belt to match. However, the dusting I used to experience disappeared and 500 hours later, the belt looks great. FWIW
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