Stator issue or not?

[Peder_y2k]

Problem or no? '88VR

 

The factory manual calls for a measurement of the Stator Coil resistance to be between 0.36 ~ 0.48 ohms at 68F, and my ohm meter measures 0.7 ohms for each wire at the connector.

 

I'm unsure of what to do as the system keeps the battery consistently fully charged, and an onboard digital voltmeter shows 13.9v running at 3000RPM.

 

There's no apparent problem. The system works, and the bike always starts quickly hot or cold, and unused, the battery holds 12.8v for days on end.

 

Testing of the ohm meter itself by contacting the 2 leads to each other results in a reading of 0.4 ohms, so how could all the additional wire of the coil be assigned the same value? It should be higher for all that length in bulk that forms the coil (longer wire = higher resistance). Seems like the 0.7 ohms would be more correct for the stator coils.

 

Input?

 

-Pete, in Tacoma WA USA

[MiCarl]

If the leads read 0.4 ohms you need to subtract that from your test result. So you're measuring the coils at 0.3 ohms. BUT, given the amount of internal resistance in your meter I doubt it precise enough to give you a reading with the accuracy you are seeking.

 

Since they all read the same, and assuming you checked for shorting to ground, I'd say you're safe to assume the stator is testing OK.

[bongobobny]

Yes, unless you have a more expensive meter like a 'fluke I would not trust low value readings to be that accurate...

[Flyinfool]

:sign yeah that:What they all said.

 

It takes an expensive meter to accurately measure the stator resistance. The best you can do is to verify that they all read the same and that there is no short to ground.

 

The .4 ohms that you see when you put the leads together is a combination of the lead resistance and any calibration error inside of the meter, you need to subtract that .4 ohms from anything that you measure. If you look at your test probe wires, they have very thick insulation but the wire is very small AWG inside of there, the wire that the stator is wound with is a much heavier wire than your test leads. That is why its reading is lower than you expected, the heavier the wire the lower its resistance per foot.

 

If you have 13.9 volts at 3000 rpm with everything on the bike turned on, then all is most likely just fine.

[Peder_y2k]

Thank you all for responding. Now I know more than I did before. I'm concluding there is NO issue with the generating system.

-Pete, in Tacoma WA USA

[dna9656]

Pete;

A wise old man once said to me "Son; if it ain't broke, don't fix it." Seems to me this is applicable here too. All 3 windings reading about the same, digital VM on board reading 13.5VDC or a LITTLE better, no charging issues...man it just don't get any better than that!

Edited June 26, 2014 by dna9656