Jst to confim Vision Gods

[xz550uk]

Hi All

I have no resistance from the 3 white stator wires ( 1 to2 , 1 to 3 , 3 to 4 ) ....all 0 ... the battery is showing 12.7v at 2k revs..

I need to change the stator ?  ....can any one tell me where I can buy a decent new one that wont cost more than the bike...

Thanks Vision Gods.....

[dingleberry]

do you have access to a machine shop?

[dingleberry]

Just found this thread. http://ridersofvision.net/rovforum/index.php?topic=14688.0

[Ken Williams]

The information you provide doesn't indicate you need a stator.  The stator wire resistance should be low.  Depending on your ohm meter, the readings may be indistinguishable from zero.  Check the stator wire to ground resistance.  It should be high, megohms.  Also look for localized overheated areas of the wiring.  If ohm measurements are good and no burnt areas are present, then the stator is likely good.  To check voltage output, measure battery voltage at 4k+ revs.  You should see approximately 13.4 volts. 

[xz550uk]

Hi Ken. Thanks for that. The reason im checking is because the battery isn't being charged when the bike is running. The connector between the stator and rectifier was melted ...I  changed it but no difference.. Im not an electrician but everything seems to point to the stator....going on posts by other members. Resistance between the wires should be 0.32ohms but the meter was reading zero . I checked the battery at revs between 2k and 6k but the reading didn't change . Guess I need to remove it to make sure....don't want to spend  money if I don't have to .. is it not easier just to change the stator and the rectifier ?  What do you think ?

[The Prophet of Doom]

Measuring at the battery includes the R/R in the circuit.  Before you pull your left hand cover (which will cost you $ for a new gasket) disconnect the stator and measure the AC Volts from each of the stator wires to ground.  Nominal is 14VAC at 3000RPM, but you may get up to 60VAC at higher revs.  All three wires should read the same.

Even if that shows a faulty stator, you still need to check the R/R before connecting it back together

[Rikugun]

I'd go with the AC output checks as POD said. I couldn't follow your resistance checks (where do you get the fourth wire?) but if the stator isn't open or grounded and puts out 50 volts or so it's probably viable. It's much easier to replace the R/R than stator although it may be necessary to replace both depending on your circumstances. Good luck with it.

[Jirik]

You can find here 2 videos, how to check stator and R/R:
http://www.roadstercycle.com/Roadstercycle.com%20Videos.htm

[xz550uk]

Hi. Just to confirm i measured resistance beween 1 and 2 , 1 and 3 , and 2 and 3 of the white stator wires. No output. The electrical terminal between the stator and the rectifier was melted... ive since replaced with a new connector.

Just so im clear.... if the rectifier stops working then the dc power will come straight from the battery which means when the bike is running the battery volts will go down ... correct ?

My battery reads 12.4 v not running and then 12.7 when running regardless of revs.

Im not an electrician just trying to get my head around the logics.

One or both are not working properly...is it not best practice to change both together?

[Re-Vision]

Hi. Just to confirm i measured resistance beween 1 and 2 , 1 and 3 , and 2 and 3 of the white stator wires. No output. The electrical terminal between the stator and the rectifier was melted... ive since replaced with a new connector.

Measuring resistance between the three white wires should indicate a low reading in Ohms. "No output" does not compute as this is what we look for when engine is running and stator is generating sine waves (output power). We need to know resistance between white wires as well as resistance to ground to determine condition of stator. Your melted connector indicates excessive power has been dissipated and your stator may well be damaged also.

Just so im clear.... if the rectifier stops working then the dc power will come straight from the battery which means when the bike is running the battery volts will go down ... correct ?

Stator and rectifier are for charging the battery, DC power always comes from the battery and Voltage will diminish under load unless charging circuitry is working properly.



My battery reads 12.4 v not running and then 12.7 when running regardless of revs.

Looks as though your charging circuitry is not working properly.

Im not an electrician just trying to get my head around the logics.

Trying to help.

One or both are not working properly...is it not best practice to change both together?

Purpose of troubleshooting is to determine what is bad, because failures of stator or rectifier can damage or weaken one another it often requires that both be replaced. Proper troubleshooting can save considerable time and money by not changing out good components.

BDC

[xz550uk]

Thanks Re-Vision....and all.  Will test resistance to ground and if volts are low then ill change both. Thanks for all the advice....life is a learning curve and thanks to you guys im learning all the time.  Just want to get her back on the road for the summer so I can see why all you guys rave about this bike.

Just ordered a new thermostat from my local dealer who suggested I bought a new bike and not waste my time "with all that old stuff"   . What a cheek !  They'll change there mind when they see her for the MOT.... and here her of course..... sorry Re-Vision........ i'm into my rock and metal so loudness is my thing......hope that explains. And yes I am an old rocker 45 going on 18.........im never growing up.....

[xz550uk]

Just measured volts from each stator wire to ground a 3k and was showing 0.2 v aprox from each wire. Guess the stator is toast.

[fret not]

Just to be very clear, you did this test with the motor running?

[xz550uk]

Yes the engine was running.

[Ken Williams]

Assuming you had the R/R connected when you measured voltage between ground and stator wires, the voltage should range roughly from -.7 to +15 volts with the frequency a function of engine RPM.  The meter indication of this voltage will depend on the design of the meter.  Use an oscilloscope or at least a true RMS meter if you really want to gain an accurate representation of this voltage.  If you are attempting to determine if the stator is shorted to ground, with the stator not connected to the R/R, measure resistance between the stator wires and ground.  It should be a large value, probably megohms. 

[xz550uk]

I checked the voltage output of the stator wires to ground with the rectifier detached and bike running. It showed 0.2 v. . I checked the resistance to ground of the stator wires and showed very low ohms . Battery isn't being charged. When everything is attached and bike is running I'm only showing 12.7 v at the battery.  The connector was melted between the stator and rectifier when I bought the bike. Connector has been replaced. 

[Ken Williams]

Assuming you checked the resistance to ground of the stator wires with the stator not connected to the R/R and you measured very low ohms, the stator is bad.  It must be replaced or rewound. 

[pinholenz]

The voltage from the Stator is 3 phase AC, whereas the voltage from your battery is DC. At the risk of sounding patronising, are you sure that the voltages you measured were with the VAC setting on the meter.? Secondly to measure the AC voltage from the running motor, you must measure BETWEEN the stator wires - not to ground. Voltage will depend on the RPM of the engine. Any where between say 18 volts alternating current at idle and 50 VAC at higher revs. (If you have actually done this, please ignore me!)

Before you assume your stator is toast, check through this test sequence  (From: http://www.cycleelectricinc.com/Diegnosing%20Alternators.htm)

On a three-phase system there are three separate windings hooked end to end. You need to test the voltage on each set of windings. The plug has three pins. First take a voltage reading between pin one and pin two. Then pin one and pin three. And finally pin two and pin three. This will test all three windings. All three should read the same voltage at the same RPM.

A stator that is shorted to ground may still produce full AC voltage from pin to pin. The problem with this is the rectifier changes the AC current to DC current and then uses the ground as one leg of the DC. When the stator shorts to ground the AC and DC get mixed together.

Testing for shorts to ground

The best way to test for shorts to ground is with a 12-volt test light. Sometimes an ohms meter will not pick up a short to ground. The light test is better.

Using a standard automotive test light, connect the ground clip to a good ground. Test the light by touching the probe to something positive such as the positive battery terminal. The light should light indicating you have a good ground. Now you are ready to start the test.

Unplug the regulator from the stator and start the motor. Probe each stator pin with the test light one at a time. If the bulb lights when connected between any of the stator plug pins and ground the stator is shorted and needs to be replaced.

If you get proper AC voltage and the stator is not grounded (no light) the stator and rotor are good. At this point you can assume the problem is either a bad connection between the regulator and the battery or the regulator is bad.

Good luck

[xz550uk]

Have now fitted new stator and rectifier ( From Elextrix World ) and now have 14.4v at the battery at 3k revs....my charging system is back....where have you been ? ....... at a cost though...... more than I paid for the bike but its worth it.

Front rocker cover gasket change next and then an MOT......about time !!

[Rikugun]

Front rocker cover gasket change next and then an MOT......about time !!

Good time to check valve lash if overdue.
Oh, and congrats on having a healthy charging system again.   :)