S4R won't start, help me diagnose!

[nizfiz]

What did you use as a load for the load test?  11 volts (assuming your open cell voltage test is correct) is a discharged battery.  Why would you expect a higher reading with the key on and not running?  You are putting a load on the battery without the charging system operating.  It will read less.  9.6 while trying to start with open cell of 11volts?  I'm shocked it was that high.

First make sure the battery connections are clean and tight.  Bad connections could explain your wacky numbers.   Take them apart, negative first.  On reassembly, negative last.  Then charge the battery until it reaches at least 12.65 volts.  If the battery does not reach that voltage, recycle time.  If it is a 10 AH battery at about 1.5 amp charging rate this will take about 6.6 hours, assuming your battery was indeed reading 11 volts..   Now load test.  The load should by textbook 3X the amp hour rating or 1/2 the cold cranking amps.  Now that you have a either replaced the bad battery or determined yours is still good start the bike.  You should read 13.5-14.5 volts at 3K rpm.  If not hit MonstaSR2's link.

I think you guys are reading into what I did a little too much. I shouldn't have done the load test. I'm just saying I used it on the discharged battery and it said that it was fine. I realize that that was useless because it's discharged.

I will do everything else you said.

[OzzyRob]

From what he's described, the fried battery & then the testing of the reg, the reg is stuffed.

The link I gave to ducati.ms has 3 really good papers on testing the reg/rect circuit.

[nizfiz]

I did the testing above today. Yesterday I charged the battery to 12.26 V. I got back to it today and it was at 12.1 V.

The bike started easily

At 2500 RPM, the voltage at the battery was 11.9 V

Voltage between R/R output (red) and battery (+) was varying but no higher than -0.17 V

Voltage between R/R output (black) and battery (-) was varying but no higher than 0.2 V

Started engine again easily, tested voltage at the battery up to 5000 RPM and it was 11.7 V or so with no variation

Tested the resistance between the 3 yellow wires off the stator. All between 0.2-0.3 Ohms. (Strange because the document above says the resistance should be 4-6 Ohms between each of them). Is this my problem?

The next tests made no sense to me because I only have 3 wires coming off the stator, not these extra ones they're talking about.

Instead, because I was unsure, I checked the voltage on the output of the R/R (between the red and green pins). It was 10 V at idle and up to 17 V with some throttle. I didn't go higher because that seemed way too high to me. Hope I didn't fry my voltmeter.

Then I bench tested the R/R:

Top Diodes, Forward Bias: PASS: 0.559

Top Diodes, Reverse Bias: PASS: all show OL

Bottom Diodes, Forward Bias: FAIL: all show OL

Bottom Diodes, Reverse Bias: PASS: all show OL

So I'm pretty sure something is wrong with my R/R. I think my battery is alive and capable of charging, holding a charge and starting the bike repeatedly. I'm not sure about my stator... the tests asking for wires other than the yellow ones makes no sense to me.

Help with analysis?

[suzyj]

My stator winding resistance is 0.4 ohms, so your stator sounds pretty good.

Agreed that your rectifier/regulator is probably shot. Worth carefully checking connectors though before you bin it.

Time to upgrade to MOSFET, methinks.

[Howie]

Stator is probably good, but try this if you have an AC meter:
At least 28 volts at 2000 RPM, 33 volts at 6000 RPM at each stator wire.

[suzyj]

Stator is probably good, but try this if you have an AC meter:
At least 28 volts at 2000 RPM, 33 volts at 6000 RPM at each stator wire.

Be careful measuring an unterminated stator. The voltages are large enough to bite. Edison used your stator to kill cats, apparently.

[OzzyRob]

Be careful measuring an unterminated stator. The voltages are large enough to bite. Edison used your stator to kill cats, apparently.

Stupid cats 

[nizfiz]

Stator is probably good, but try this if you have an AC meter:
At least 28 volts at 2000 RPM, 33 volts at 6000 RPM at each stator wire.

Is this the voltage between the yellow stator wires, or between each of them and the frame?

[Speeddog]

Between the yellow stator wires, 3 readings.

[nizfiz]

New voltage regulator installed and the running voltage at the battery is ~14.2 and no higher than ~14.5 as I rev up. Problem fixed I think!