how to test stator removed from bike?

15 replies to this topic
  • spokexx

Posted June 08, 2011 - 11:44 AM


(2004 WR450F) First let me point out that I modified my stator according to the BajaD kit about 2 months ago. My stator is back out and im wondering how can i test it to see if it's ok. Between the yellow and white wire im getting .8 ohms (BD says it should be approximately .5 in their instructions. Am i significantly out of range?).
What else can i check?

thank you.

  • William1

Posted June 08, 2011 - 12:14 PM


I'd email or call BD. Also, check for continuity to ground as you have floated it, there should be an open circuit, test each lead seperately to the iron where the screws go in, confirm there is no continuity to ground.

Why do you think there is something wrong with it? Did you test it for output installed Before the reg/rect?

  • spokexx

Posted June 08, 2011 - 12:42 PM


William, I was hoping youd pop up :ride: My previous battery went dead, wouldnt even crank the engine after rechargin it. Thought I could still ride the Durty Dabbers dual sport by kick starting it and only made it half way (60 miles) when the bike was misfiring horribly. I guess battery voltage dropped way low, i even had to keep the headlight off just to keep the engine going. ANyway, just got my new Shorai battery yesterday and the bike runs great again, but im not seeing 14.1-14.8v when i rev it. Only 13.5v (same voltage when the bike is off). Did the resistance test according to manual(red probe on yellow wire in harness and black probe on ground) and saw nothing on dmm. hmmmmm.
Yes, there is no continuity between the yellow and the iron and the white and iron.
I could ride it, but eventually the battery will drain, correct?

  • William1

Posted June 08, 2011 - 01:27 PM


Ok, at least you know it is not shorted to ground and that there is some continuity between the white and yellow leads. Too bad you did not attach them directly to the meter and check for voltage at idle and at speed before you removed it.
You cannot go by the book as you have a modified stator. BD should have the specs.

Thing here is, it is probably your stator but not definitely, based on what we know at the moment. Could be a bad connector, poor ground even a bad rect/reg (though doubtful).
Speak to BD, get the spec's the stator should test at. Check all your connections.

Yeah, you ride it like it is and you probably will kill the battery.

  • RickyStator

Posted June 08, 2011 - 02:09 PM


.5-.8 ohms should be fine. We are talking less than 1 ohm, generally on a stator like this I would say the resistance should be between 0-1 as all meters are no created equal. If you want to know for sure the status of the stator reinstall it and do a load test on the stator. this would be done be hooking a light bulb directly to the output of the stator and measuring the voltage. In this case you should be able to run about 100 watts right off the stator if it is OK. To do this start the bike and then unplug the yellow and white wire from the R/R. Then wire your 100 watt bulb across the yellow and white wire. Give the bike about 1/4 throttle and measure the voltage across the bulb, if it is OK you should see at least 12VAC across the bulb. You can pick up a 100 watt H3 bulb at Walmart fairly cheap. This is the only way to know for sure what the stator is doing.

  • William1

Posted June 08, 2011 - 02:15 PM


Good to know, thanks Ricky! (I am going to save this tidbit and reuse it, hopefully pass it off as my own brilliance......)

  • spokexx

Posted June 08, 2011 - 02:59 PM


Ok, at least you know it is not shorted to ground and that there is some continuity between the white and yellow leads. Too bad you did not attach them directly to the meter and check for voltage at idle and at speed before you removed it.

i can put it back in there and see what im getting. But Do you mean pull the yellow/white wire connector(coming from the stator) out of it's mate(tucked up under the frame top tube) and stick the dmm probes in there to see what AC voltage im getting?
I can also try what Ricky suggests.

Edited by spokexx, June 08, 2011 - 03:20 PM.

  • William1

Posted June 08, 2011 - 04:21 PM


Yes. Do that with the 100 watt bulb as RS suggests and have the meter connected. Under load is always the best test.

A man in a chair with running shoes on may look fast but put him on the track to be sure.

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  • L. Euler

Posted June 08, 2011 - 08:46 PM


When you said that you read .8 ohms and expected .5 ohms, did you verify the DMM lead resistance? They usually run .1 to .4 ohms depending on condition and quality. This adds to your reading. Higher quality DMMs have a zero function to compensate.

  • spokexx

Posted June 09, 2011 - 05:08 AM


hmmmm i did not. i will assume my dmm is not of higher quality. So maybe my reading is actually .5

  • spokexx

Posted June 09, 2011 - 08:28 AM


Well, i didnt get to the 100watt bulb test yet, it's ridiculously hot today and i cant stay in the garage more than 20mins. But heres what i did find out. Engine running and the yellow/white stator wire connector removed from mate i have 25vAC idle and up to 80vAC revving. Connected back in and engine idling with light on i have a rock steady 13.29vDC at the battery. Revving doesnt make it go up or down. But it doesnt drop, either. With the light off and idling, the voltage will climb up to around 13.60vDC and stay there.
Engine/ignition/lights off, battery rests at around 13.25v. So it seems there is charging going on. Right?
My last battery died, i believe from internal injury. It wouldnt charge even with the tender left on it overnight. There was even a bulge on the top of it's case. But i never did test my charging system when i installed the ds kit 2 months ago. I just went riding and the bike worked fine until the battery died a month and a half later.
Im waiting for a reply from BD on the charging specs. I'll try the bulb test when the temp around here gets below 90.

  • miweber929

Posted June 09, 2011 - 09:55 AM


Without doing a ton of searching (something I bitch about all the time) don't you have to change your reg/rect after the BD change? Thought I read that somewhere a while ago, one of the reasons I haven't modded mine.....


  • spokexx

Posted June 09, 2011 - 01:11 PM


yes, i changed mine. I bought the whole kit. Well, i emailed back and forth my test results with Ryan from BD and he says it looks like it's working fine.

Edited by spokexx, June 09, 2011 - 04:33 PM.

  • William1

Posted June 09, 2011 - 05:01 PM


Voltage should be higher, in the 14.5 range. Did you check every connection?

  • spokexx

Posted June 11, 2011 - 06:08 PM


I agree, William. Their website says voltage should rise from 13.6 to 14.
If no change, it says the R/R needs replacing. I emailed them for a replacement. I did check all the connectors, removed and reconnected.

Edited by spokexx, June 11, 2011 - 06:25 PM.

  • Tyrone Cunningham 28

Posted June 12, 2011 - 12:10 PM


I also have a sparking issue! My stator coil has been redone and I stil have a spark problem sometimes I have spark and sometimes I don't? At the moment there is no spark. Do you perhaps know what could be messing about? I would ride the. Bike then at no specific time would just die with no spark, then from time to time it comes back. Thanks


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