3 replies [Last post]
bmwridr's picture
Joined: 03/29/2018
Posts: 12

I'm sure this has been covered before, but my brain is on overload from this. hey tommy thanks for helping me last night brother!!! so this is what I have found
* I re-polarized field before I started any of the below. I also scuffed up commutator with scotchbrite and brushes both were making good contact

*disconnected both wires from f term and jumpered wired going to field and got no voltage increase ( I suspect reg is good even though it looks bad. bottom contacts were rusty and I cleaned to best of my abilitity)
*removed field and tested ohms at 61 and two yellow wires. it read 2.5 ohms (good according to rinckes book)
*armature ohms test was not good. it reads 2.5 ohms from commutator to ground, and same from commutator to armature stack (bad according to rinckes book)
having given all this exact same info to vech this morning via email, he tells me I need regulator and that unless rotor had contacted field, 90% of time its the regulator

in closing I'm not really a part swapper. I say that the arm is shot

thanks, doug
hey jeff dean, my mom says hi

Captonzap's picture
Joined: 08/21/2014
Posts: 81
Did you tell Vech about your

Did you tell Vech about your meter readings? If so, he missed something.
There should be continuity between all the commutator bars, and none between them and any other portion of the armature. All of this being measured with all wires disconnected from the generator, and the brushes pulled from their holders.


bmwridr's picture
Joined: 03/29/2018
Posts: 12
capt zap, I gave him exact

capt zap, I gave him exact same details as I have on here, and after questioning his reply to my email he did say that if there was continuity between commutator and arm stack or ground that arm was bad.
I'm going to get a regulator from zophias even though when I did a bypass test on it nothing changed. since I put a whole new harness and a new coil from vech, I might as well put on new reg

thanks again to tommy for his help and to all that have replied to different posts I have put on here to resurrect this beast

cheers till next time

johnpst's picture
Joined: 03/22/2016
Posts: 82
Simple continuity and electron flow, path of least reaistance

I don't know the whole conversation but, if there is continuity to the stack/ground through commutator, then the path of least resistance is to the crankshaft and not to the brushes. The insulation is shot.

There are other test you can do but, you've run into a fatal flaw. If testing was done correctly, you're done.

It's possible to rewind but, not too many shops do that work (well) anymore. Check around.

It is also possible your voltage regulator is giving you trouble but, that's a separate issue. Work one problem at a time. Your choice which one to tackle first but, you have data on the armature. It indicates failure. If you are confident you've performed the test properly, trust what you are seeing.

Let us know if you have any questions. We're all root'n for ya.

Good luck.


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55 - R50, 06-R1200RT, 96-M900, 10-TU250x

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