View Full Version : Noisy Sporster Alternator Conversion Kit - Is this normal?

07-11-2014, 12:43 AM
Howdy all,
I have a question for any of those out there that run a Sportster alternator conversion kit - I have tried to find a solid answer from other sites, etc. about the NOISE! I know generators make noise, but the alternator kit, once the oil thins out after riding for a while it makes a really nasty sound - kind of like a steam engine - that chugga chugga chatter would best describe it. Anybody have input on this?

Here is my '74 XLH Sportster ~


07-11-2014, 9:44 AM
I'd pull it, determine what bearings live therein, and buy the highest quality replacement bearings available from a bearing supplier.

Measure ID/OD/thickness with a micrometer or caliper as well as getting any numbers off the bearings. I'm not deep into electric motor/generator rebuilding so I defer to those who know more about bearing classes and materials.

You could contact local industrial electric motor/generator repair outfits. Best to visit with your alternator in hand. They'll have the pullers to do the swap if you don't.


Post pics of your alternator internals etc so this thread helps others. If someone recognizes the specific alternator and what else the basic alternator fit before it was modded for motorcycle use
that may be of help. Just as Denso starters used on Harleys have millions of kin on automobiles, so will all but completely custom alternators.

Always post DETAILED threads when asking tech questions so the 33 hive mind may better help you.

I'm curious as I want an alternator for my Ironhead too.

07-11-2014, 10:11 AM
Sounds like a incorrect install if it's new unit.

07-11-2014, 10:15 AM
If your trying to save weight or want something different the alternator kits are cool but nothing is as reliable as cycle electrics all in one generator

07-29-2014, 6:49 PM
i've been running 1 on a 1980 iron head and it is a little noisy but not that loud . been running it for 8 years no issues replaced the regulater 1 time