High power alternator vibration.

[Sidcar]

High,
I’ve fitted an Arrowhead high output alternator to my ‘95 GL1500. It charges lustily even at idle but now there is “gear chatter” especially when cold but loading the system by putting the lights on does damp this down and vibration until 3000 rpm when the engine becomes it’s usual smooth self.
I fitted a new set of coupling drive inserts and that helped a bit.
Is this normal with high output alternators?
Just to be sure it was the new alternator I put the old one back and the engine became it’s old smooth self.
Any help/ideas appreciated.

Sid

[Rambozo]

Maybe have the balance and runout checked by a good alternator shop?

[Swagonmaster]

I had the very same thing happen when I put my 95A alternator in and also used new rubber inserts. Another poster with the issue called it a resonance but it seems that what ever you call it there is no harm done that I can see other than to your peace of mind.

[rider1939]

I can't see where this can be a good thing, ASSUMING it is out of balance. Anything out of ballance is destructive, either in the short or long term.

Get it out and to someone that can balance it, or return it.

[Swagonmaster]

Ok, I'll give you that so maybe take it to an alternator shop and have them spin it up or if you have access to an impact wrench spin it with that and see if it is out of balance or just has a side effect of the greater charging drag.

[gford]

Same here, put in a 95 amp and a lot of vibration until 2500 rpm, replaced with 40 amp and the bike was smooth as butter.