Generator making a funny noise

[Rex_A_Lott]

My generator started making a funny noise. The best way I can describe it is the way a modern car sounds when its been run hot and the radiator cap has lifted to blow off some steam. Revving it up would sometimes make it quit, but not always. I could give it a sharp rap with a hammer and it would stop, but would start over again after a few minutes at a different engine speed.
I dont believe it was a bearing, it wasnt that sort of sound.
I swapped it out with another I had bought at the swap meet, but when I tear into this one, what should I be looking for?

[redmodelt]

Bearings or bushes. Also if the 3rd brush output is not properly set can make a whine like sound.

[C26Pinelake]

You have it apart, why not replace the bearings and bushings if everything else is okay. The parts are not expensive, put in new brushes while you are at it. Wayne

[SeaSlugs]

Is it kinda growley or "grrrrr"ing at you like a power steering pump?

[Tom Wesenberg]

A V belt can also make a noise. Have you lubed both ends of the generator?
The oil hole for the front bearing is under a flap that needs to be pushed to the side.

[zzlegend]

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I have one on an engine that I bought and its a good runner. But kept getting a high squealing type whistle out of the generator. Had to rev it a bit to get the charge on the gauge to work. Took it apart and found one of the brushes upside down where it was not riding flush on the armature. It was just catching an edge. Turned it over and all is good now. Charges right away now. Funny how a small thing like that could make that noise. Just my 3 cents.

[Rex_A_Lott]

Originally Posted by Tom Wesenberg

A V belt can also make a noise. Have you lubed both ends of the generator?
The oil hole for the front bearing is under a flap that needs to be pushed to the side.

Yes, oiling it while it was running was my first thought...no difference. This was a generator I took off another car, it had been "rebuilt", but had been sitting for a long time. I put it on this car, and the cutout was bad, so I put a Fun Projects V/R on it and adjusted the third brush. It was OK for a while but it only ran a few hundred miles before it started with the racket. We have our little town parade tomorrow, so I just swapped on another one. I'll take it apart for a better look when I get the time.