I've replaced the alternator, aligned the pulleys as best I could with a true, flat rule, and I still am eating belts. Apparently the PO had the same problem which explains why there were so many different size belts on board. The Alternator was shot and I replaced it. The belts are lasting longer but still getting eaten up. I've used a straightedge which touches the inner and outer side of two pulleys. My thought is the bearings might be worn, causing the pullys to run at an angle with tension on them. There is no visual signs of problems on any of the faces. I use standard V belts. My next step would be to replace all V belt pulleys with serpentine pulleys. Any thoughts or help?
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Take a good hard look at the v-groove surface
Such sheeves are pressed from mild steel and mild steel is easily subject to rusting. If the surface becomes roughened due to prior rust / polishing / rust / polishing by the v-belt, its usually time to have the surfaces 'dressed' back to flatness or simply replace the sheeve with new. If the surface is even slightly roughened by prior rust, the belts will wear very fast. For some reason Yanmar water pump sheeves are especially prone to such roughness. Such roughness 'grows' on sheeves that are not constantly and continually run. When not running the engine for long periods, consider to spritz on some corrosion inhibitor wax such as "BOESHIELD".
Such sheeves are pressed from mild steel and mild steel is easily subject to rusting. If the surface becomes roughened due to prior rust / polishing / rust / polishing by the v-belt, its usually time to have the surfaces 'dressed' back to flatness or simply replace the sheeve with new. If the surface is even slightly roughened by prior rust, the belts will wear very fast. For some reason Yanmar water pump sheeves are especially prone to such roughness. Such roughness 'grows' on sheeves that are not constantly and continually run. When not running the engine for long periods, consider to spritz on some corrosion inhibitor wax such as "BOESHIELD".
Notched Belt
What type of belt are you using? Alternators have a very small sheave. There is a minimum bend radius for each belt. It sounds like the belt you are using is operating below it's minimum bend radius. You should be able to find a belt that has what looks like teeth cut into the ID. This is called a notched belt. This allows for a much tighter bend radius and helps the belt stay cooler. There is also a HP limit per belt. High output alternators may need to go to a two belt system to transmit the increased HP. I posted a picture of a notched belt that is on E bay so you get the idea. Talk to a good automotive parts company like NAPA and they should be able to cross reference a notched belt to fit your application. Dan
What type of belt are you using? Alternators have a very small sheave. There is a minimum bend radius for each belt. It sounds like the belt you are using is operating below it's minimum bend radius. You should be able to find a belt that has what looks like teeth cut into the ID. This is called a notched belt. This allows for a much tighter bend radius and helps the belt stay cooler. There is also a HP limit per belt. High output alternators may need to go to a two belt system to transmit the increased HP. I posted a picture of a notched belt that is on E bay so you get the idea. Talk to a good automotive parts company like NAPA and they should be able to cross reference a notched belt to fit your application. Dan
Notched belt
For what it's worth, I too have a Perkins (different model) and it has a notched belt. I decided this winter to get a second belt for a backup (although I haven't had any problems) and took the belt to NAPA, and 2 other automotive parts places and not only did they not have notched belts the right size, it was really hard to find any belt the right size. My notched belt has a Bridgestone lable and number on it but it doesn't cross reference with anything. I finally got a smooth one that is close and I have installed it. Next spring we'll see how it works but I'm sure keeping the notched one handy just in case.
For what it's worth, I too have a Perkins (different model) and it has a notched belt. I decided this winter to get a second belt for a backup (although I haven't had any problems) and took the belt to NAPA, and 2 other automotive parts places and not only did they not have notched belts the right size, it was really hard to find any belt the right size. My notched belt has a Bridgestone lable and number on it but it doesn't cross reference with anything. I finally got a smooth one that is close and I have installed it. Next spring we'll see how it works but I'm sure keeping the notched one handy just in case.
Alternator Rating?
If everything is square and true then it sounds as if the alternator needs more power than a standard Vee belt can handle. Do you have an up-rated alternator? Many of these up rates really need a double pulley and twin belts.
If everything is square and true then it sounds as if the alternator needs more power than a standard Vee belt can handle. Do you have an up-rated alternator? Many of these up rates really need a double pulley and twin belts.
When you solve your problem let me know so
you can help solve mine.
Seriously, all good advice here. I've only seen one double belt setup on a Yanmar. It was home made and wouldn't work for me. I've had to do all of the remedial work outlined here and I'm now getting good belt performance. Finally. 1. Check for rust. If so, replace. 2. Alignment. Another tool to check with is a dowel. With the belt off, put a dowel (like what's holding a paper towel roll) in the pulley. It will point perfectly to where the belt wants to go. Vee belts have a maximum run-out of 15 degrees. 3.New alternator means new stuff but if you can't control startup output you can still be overloading the belt with a HO alternator. 4. If you find a serpentine kit,,,,PLEASE LET ME KNOW! See what I mean?
you can help solve mine.
Seriously, all good advice here. I've only seen one double belt setup on a Yanmar. It was home made and wouldn't work for me. I've had to do all of the remedial work outlined here and I'm now getting good belt performance. Finally. 1. Check for rust. If so, replace. 2. Alignment. Another tool to check with is a dowel. With the belt off, put a dowel (like what's holding a paper towel roll) in the pulley. It will point perfectly to where the belt wants to go. Vee belts have a maximum run-out of 15 degrees. 3.New alternator means new stuff but if you can't control startup output you can still be overloading the belt with a HO alternator. 4. If you find a serpentine kit,,,,PLEASE LET ME KNOW! See what I mean?Check the pivot bolt
When my Balmar was installed by the PO, he put an undersized pivot bolt in. I guess that was to allow the thing to install easily. Needless to say it came out of alignment under load. That also allowed the vibration to elongate the holes which made the problem even worse. I finally had to get an oversize bolt and ream the old holes to get a tight fit. Good luck and Merry Christmas.........
When my Balmar was installed by the PO, he put an undersized pivot bolt in. I guess that was to allow the thing to install easily. Needless to say it came out of alignment under load. That also allowed the vibration to elongate the holes which made the problem even worse. I finally had to get an oversize bolt and ream the old holes to get a tight fit. Good luck and Merry Christmas.........
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