stator resistance values

[revilo]

Hi guys, I'm trying to determine if my stator is pooched. 1.8 ohms resistance between all three legs. According to the quick test guidelines, that's a bad stator. However, they are all still open loop, and produce over 50 volts when the engine is revved past 5000.

What is happening when the resistance goes up like that? I've got the stator wires running direct to the mosfet R/R. I discovered a short on one of the main power wires, would that kind of stress ruin the stator in this way?

Thanks for the help in advance, I've learned a ton from reading all your posts, but still have lots to learn and truly appreciate the explanations.

[bwringer]

Have you tried a different meter to verify your readings? Also, you might check it again with fresh batteries in the meter.

And just to verify -- you are testing resistance with all the stator legs unplugged and no other connectors between the stator and the meter, right?

Since all three readings are the same and it's producing AC voltage over 50, you're probably fine, at least for the moment.

The overload from the short might have shortened the stator's life or it might have done nothing much at all. Personally, I'd open it up if possible and look for overheated spots. Or just run it and see what happens.

[posplayr]

There are resistance measurements in the Quick Test.

[Steve]

What does your meter show when you touch the two leads together?

Subtract that number from your 1.8 ohms reading to get the true resistance of the stator.

.

[revilo]

What does your meter show when you touch the two leads together?

Subtract that number from your 1.8 ohms reading to get the true resistance of the stator.

.

Thanks for the useful feedback. The meter resistance is .05, and it does have fresh batteries. That's still 1.3 ohms of resistance, too high according to the stator papers. I did unplug the stator before testing. I'll have another go with another multimeter, though.

Unfortunately, after running the quick test, something is definitely amiss. Values are basically 12.5 volts across the board when the engine is running. Found a few tutorials on how to troubleshoot a mosfet R/R, and will hopefully figure it out ASAP, as I may be able to pursue a warranty claim. I purchased and installed a new stator and mosfet R/R last year from RM Stator, then had to almost immediately put the bike away for the winter before I could check if everything was hunky dory (multimeter had died). Fast forward to this year, and the bike has drained it's battery after only a few kms, leading me to question if I got a faulty part, or whether a short could have toasted the stator and/or R/R. Very disappointing, as I'm only near my GS a few weeks of the year, and want to ride it instead of work on it!

[Steve]

Whether or not the stator is good remains to be seen, but you WILL want to be replacing that MOSFET R/R soon.

.

[posplayr]

Hi guys, I'm trying to determine if my stator is pooched. 1.8 ohms resistance between all three legs. According to the quick test guidelines, that's a bad stator. However, they are all still open loop, and produce over 50 volts when the engine is revved past 5000.

What is happening when the resistance goes up like that? I've got the stator wires running direct to the mosfet R/R. I discovered a short on one of the main power wires, would that kind of stress ruin the stator in this way?

Thanks for the help in advance, I've learned a ton from reading all your posts, but still have lots to learn and truly appreciate the explanations.

Thanks for the useful feedback. The meter resistance is .05, and it does have fresh batteries. That's still 1.3 ohms of resistance, too high according to the stator papers. I did unplug the stator before testing. I'll have another go with another multimeter, though.

Unfortunately, after running the quick test, something is definitely amiss. Values are basically 12.5 volts across the board when the engine is running. Found a few tutorials on how to troubleshoot a mosfet R/R, and will hopefully figure it out ASAP, as I may be able to pursue a warranty claim. I purchased and installed a new stator and mosfet R/R last year from RM Stator, then had to almost immediately put the bike away for the winter before I could check if everything was hunky dory (multimeter had died). Fast forward to this year, and the bike has drained it's battery after only a few kms, leading me to question if I got a faulty part, or whether a short could have toasted the stator and/or R/R. Very disappointing, as I'm only near my GS a few weeks of the year, and want to ride it instead of work on it!

If we believe your numbers your stator is bad. You understand since you do not seem to follow direction in the formal stator pages tests, there is a certain amount of guessing required to come to that conclusion.

http://www.thegsresources.com/statorpapers4.php

Is the MOSFET R/R faulty? No but by design it will stress your stator.

[revilo]

Hi all, after thorough testing and troubleshooting, I thought you'd appreciate an update for posterity. The regulator rectifier was faulty, and I received a replacement under warranty from RM Stator. Their service has been excellent.

POS, you presume I did not follow the quick test and other guidelines. You would be wrong. In addition to using the resources in the stator papers, I contacted the manufacturer and worked with their techs to troubleshoot. The resistance values I am seeing are within their service limits (particularly after factoring in the meter resistance values, thanks for the pointer Steve), so no, the stator is not faulty. I've learned a lot from the process and am much more confident about using my multimeter and troubleshooting electrical problems now. I also used the downtime to replace the fusebox with a new chip type and rehab and solder all charging system wiring. Thanks to all who offered encouragement, you guys know and understand how bad it feels when the bike is down, and how good it feels to get her going again! Put in the replacement regulator as soon as I received it, and a quick test proved successful. Happy days, I can enjoy my last week of riding before I head back overseas.

[Nessism]

If you are reading 1.8 and your meter is off by .05 that means your actual values are 1.75, not 1.3.

50 VAC is weak. A good stator will put out about 50% more voltage than that, and even if it does (at no load) when under load it may not provide the charging system voltage you need. I recently went through this on a bike that had 75 VAC but could only make 13.8 VDC at the battery.

[Buffalo Bill]

Meh…thanks for the timely post and link to Ye Olde Statore Paperes.
Just another clue I'm getting old too.

[revilo]

Im just happy its all working again. I also installed a gammatronix led voltage monitor, so I should know about an issue if one occurs in the future. Again, thanks for all the help and an outstanding resource here.

[posplayr]

Hi all, after thorough testing and troubleshooting, I thought you'd appreciate an update for posterity. The regulator rectifier was faulty, and I received a replacement under warranty from RM Stator. Their service has been excellent.

POS, you presume I did not follow the quick test and other guidelines. You would be wrong. In addition to using the resources in the stator papers, I contacted the manufacturer and worked with their techs to troubleshoot. The resistance values I am seeing are within their service limits (particularly after factoring in the meter resistance values, thanks for the pointer Steve), so no, the stator is not faulty. I've learned a lot from the process and am much more confident about using my multimeter and troubleshooting electrical problems now. I also used the downtime to replace the fusebox with a new chip type and rehab and solder all charging system wiring. Thanks to all who offered encouragement, you guys know and understand how bad it feels when the bike is down, and how good it feels to get her going again! Put in the replacement regulator as soon as I received it, and a quick test proved successful. Happy days, I can enjoy my last week of riding before I head back overseas.

I'm glad you have your bike running and you feel newly empowered in your ability to solve problems. Unfortunately for anybody else reading this I would hope they would not take it as any indication of how to diagnose charging systems problems. I guess there is one exception, your thread does highlight how to zero adjust an ohm meter. Considering how useless an ohmeter is if diagnosing charging systems , don't get too excited about that small amount of praise.