Alternator belt

Guest · Post by **Guest** » Thu Jul 08, 2004 7:13 pm

There is a problem with some of the Balmar alternators. Bearings seize and then the belt breaks. Also the mounting bolts are the wrong size. Check with your dealer. Tom Burrows, Warrior 2, 508-737-6789

[Posted by: 12300
]

Guest · Post by **Guest** » Wed Nov 10, 2004 1:47 pm

I had my Balmar rebuilt already, the pully was the wrong size and it ate the belt and made a horrible mess of black powder that wrecked the alternator. And the bolts where the wrong size too.

[Posted by: Michael Thompson
]

jerry · Post by **jerry** » Sat Apr 29, 2006 2:19 am

I'm hoping I've stumbled across the source of my problem- Had the boat out racing last week and had a new "burnt rubber"

Guest · Post by **Guest** » Fri May 12, 2006 9:14 pm

I had similar problems for 2 seasons until Mack Boring found that the wrong size bolt (too thin) was used to mount the alternator to the engine. If the alternator is slightly out of alignment with the engine pulleys when the belt is tight, that's a good indication that there's a mounting bolt problem. A new mounting bracket and bolt plus a change in alternator belt specification to a higher performance belt with a toothed inner surface solved the problems. (alternator also replaced undder warrantee because rubber particles from the belt gummed up the works)

Milt Gottschalk #78

[Posted by: Milt
]

jerry · Post by **jerry** » Mon May 15, 2006 1:05 am

Thanks for the info. I had the local Yanmar authorized service people to do maintenance this past week. It was a loose belt and pulleys appear to be in alignment. On inspections they said the mounting bolt was fine, but the larger Balmar alternator was hitting the mounting plate and not allowing it to slide all the way to tighten the belt. He made some adjustments to allow it to slide easier, which make tightening the belt easier as well. He did say some black belt shoot is ok, but it should be excessive.

Iâ€™ll be keeping an eye on this summer and see if the problem repeats. Hopefully, not a temporary fix. So far so good.

PS: Any idea what the official size of the bolt should be?

Jerry, Shada #44

Guest · Post by **Guest** » Sat May 20, 2006 11:50 am

Suggestions on determining if alternator mounting bolt is correct size:
1. The long bolt which goes into the bracket that holds the alternator on the engine must fit very snugly (metric size bolt I believe)
2. After the alternator is mounted and adjusted to proper belt tension, place a stiff metal straight edge against the front of both the engine and alternator pulleys. If both are flush and exactly parallel to the straight edge, the mounting bolt is probably the correct size. If the alternator pulley is at a slight angle (maybe 10 degrees), you have an undersized alternator mounting bolt which is permitting the alternator to twist out of alignment with the engine when the belt is torqued to proper tension.

After 2 destroyed alternators and 4 destroyed belts on my boat, I hope you have an easier time fixing than I did.

Milt
Rocky Racer (#78)

[Posted by: Milt
]

Guest · Post by **Guest** » Sat May 20, 2006 11:56 am

Suggestions for determining alternator alignment as source of excess belt wear:
1. The long bolt which holds the alternator on the engine mounting bracket must fit very snugly in the mounting bracket (metric size bolt I believe)
2. After the alternator is mounted and the belt is torqued to proper tension place a long, stiff, metal straight edge across the face of both the engine and alternator belt pulleys. Both should be flush to the straight edge and perfectly parallel. If the alternator pulley is at a slight angle (maybe 10 degrees), you have an undersized mounting bolt which is permitting the alternator to twist when the belt is torqued to proper tension.

Milt
Rocky Racer (#78)

[Posted by: Milt
]

Guest · Post by **Guest** » Tue Aug 29, 2006 12:37 pm

I may have a common fix for a group of boats.

My hull number is 240 and I have a Balmar alternator - installed by Yanmar - and delivered to Pearson Composites.

The Balmar Alternator has an Imperial sized pulley - where the engine has a metric pulley. The belt is a metric belt. Because of this mismatch - the belt eventually wears out.

If you have a blue pulley on your alternator - contact your dealer to arrange to have this swapped out by a Yanmar servicing company. I am not sure what the warranty period is - but mine is being covered under the warranty.

This should fix the wear issue on the alternator belt - as everything else appears to be properly aligned.

I would argue that this is a basic design flaw - and potential safety hazard - and should be replaced by Yanmar regardless of the age of the boat.

[Posted by: 24000
]

Guest · Post by **Guest** » Wed Sep 27, 2006 9:34 pm

I talked to the Balmar reps at the Annapolis Boat Show last year, and they sent me the correct pulley for the Balmar alternator. The problem with eating belts and massive amounts of belt dust seems to have been solved.

The rep was well aware of the problem from the factory, and had in fact fixed several of the problem alternators out West.

.

[Posted by: Sam Mitchener
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