Ducati Monster Forum

I have the side cover off and see a burned stator (12 of 18 "posts" are black)

Doing the stator resistance test, Ohms from yellow to yellow a.s.o. That shouldn't be a problem while the cover is off?

The other (static?) test, ground to yellows...... can it be done while the cover is off? Connect it to the engine with a wire?

(https://i.postimg.cc/xCgX1xXG/20240713_151148.jpg) (https://postimg.cc/bDDy6RHd)

Here's my meter.

200/"sound symbol" gave 0.6 on all three yellows

20K showed 0 .  before connecting. No reaction when connecting the yellows.

From ground to yellows gave no reaction either.


(https://i.postimg.cc/rw4Yhmst/20240714-183235.jpg) (https://postimg.cc/gxYDjGvY)

PM Howie. He has all the numbers in his head.

Good morning. Thanks, I have now done that.

Measured again, at 200/
0.6 between all two and two yellow combinations

Still at 200/ black against several places in the side cover itself, stator core, stator mounting bolts and the red to all three yellows. No change. Does not move from 1 in the display. Tried all ohm settings. No reaction.

OK, Ducati has no spec for stator resistance.  You want to see continuity and equal resistance.  The number will be low.  Cover on or off doesn't matter.  Did you test stator output?  Each yellow wire should produce 28 -33 volts at about 3000rpm.

This chart is a good guide  https://cdn.shopify.com/s/files/1/1091/5694/files/fault-finding-diagram.pdf?235929069374954073

Now that I think about your photo, even if everything tests OK, at some point the lacquer that insulates the winding is crispy and will eventually fail.  I wouldn't want it to fail on my trip to Italy.  Less than $200 from Ricks   https://ricksmotorsportelectrics.com/l/aftermarket-stators

Stator was new last year. So was the starter. R/R too.

Water killed the starter, the mechanic thinks. Water in the starter = water in the stator?

Any idea why I can't get results from ground to yellows? Shows 1 and does not change. From several spots in the cover and on/by the stator.

I don't know what to look for, but near where the wire goes through the starter shell, the oil looks more like grease - grey stuff that isn't possible to see through.

The brushes and stuff seen through the shell
(https://i.postimg.cc/0y7R5zgq/20240715_164920.jpg) (https://postimg.cc/RWCbXVVP)

The thing
(https://i.postimg.cc/zXsY1ncj/20240715_165018.jpg) (https://postimg.cc/zVFcCR5b)

Some of the grease looking oil
(https://i.postimg.cc/MGxknzxf/20240715_165126.jpg) (https://postimg.cc/Bjh7y9jJ)

another shot of the grease looking oil
(https://i.postimg.cc/YqGBVXb0/20240715_165144.jpg) (https://postimg.cc/ykHG3TqC)

Brushes and stuff
(https://i.postimg.cc/KY56LCvq/20240715_165443.jpg) (https://postimg.cc/d7LNcHCr)

I'm not understanding your yellow to ground 1 ???  Stater windings to the body of the stator should be infinity.

All I can think of with the starter is a combination of engine oil and debris, but I don't see a path for it to happen.

Maybe we should call koko64 to the red phone?

I want to perform the test that is black on ground, in this case the cover or other suitable ground (please suggest where) and the three yellows. I have the digit 1 in the multimeter display. It does not change while doing the test.

Didn't we/someone settle on 0.6 ohm as a good result? The Electrosport mentions much higher numbers.

Electrosport is using an any bike number.  Ducati does not have a published spec.  In my rough calculations do to rounding off, like using an assumed 12 volts, comes to about .8 ohms so your .6 ohms is probably good enough.  Too low means a short.

Any unpainted metal on the engine case that is not insulated from the rest of the engine will be fine.  Is the 1 you are reading on your meter 1 ohm or does it stand for something else?  Anything less than infinity means short to ground.

The most important test on an alternator is voltage output, in the case of your bike alternator, for each phase with the bike running.  Most important because it is dynamic, in other words how the component works with temperature and vibration.  The tests you are doing are static and used to find the defective component.  You can add vibration and heat to your static tests. 

How was the connection at the voltage regulator?

All wires in and out of the R/R look fine.

The point is to find out if I need a new stator, now, soon, later. I would like for the situation to be as clear as possible before I put the engine back together. The color suggests to replace the stator now or soon. The yellow to yellow static resistance test suggest that I can wait (, but it's just static , cold and vibration free).

This picture shows the 1 I'm referring to. That's what I see when I turn the dial to ohm and it does not change while testing. The side cover is hanging on by ducttape. It might not have good contact with the rest of the bike. I put the black probe against the cover, the steel center in the stator and anywhere I can think of. I also tried all settings on the meter. Also, of course, all three yellows. What am I doing wrong?

I guess I can procede without the ground to yellow test, but since I'm stubborn I'd like to do it with a result.

I have my credit card out. Probably just get a new stator. It'll be here in a couple of days. So far this has just cost me rain days.

(https://i.postimg.cc/3wbnHsXV/20240715_221329.jpg) (https://postimg.cc/GBGkFSSx)

Problem is I have no clue what that 1 stands for.  A 1, then spaces and finally a decimal point???  Got a manual for that meter or another meter?  I looked on the web a manual for your Brother YH-600B and it came up as equipment for respiratory diagnostics  [bang]

The decimal point moves as I change the setting, but that doesn't affect the outcome - which is 0.6 or in this troublesome attempt no change in the display.

Chinese product. I let google look for products/pages/websites from the picture. They returned two other brands selling the same meter. Electro-Tek and Wellink HL-3000. The Wellink product has/had a lot of hits on the web - mostly Chinese language - a few in English - none with any mention of a manual.

1 is over-range, high resistance. It's what it should be between the windings and case.

Thanks - so, it's an actual result? Since I couldn't see any change/movement in the display, I assumed it wasn't. When I connected the two probes I got 0.2

Is black probe on the shiny steel in the stator core ok?

Hi suzyj.  Thanks for clearing that up

I would run a magnet through that greasy oil as a test. How does it feel between the fingers? Im thinking metal particles or possible water vapour build up. What is your breather set up?

 If the voltage output numbers are insufficient then replace the stator. Looks burned up.

I'll look up starter replacements. I did one in a Multi 18 months ago. I went with what local shops use, Arrowhead iirc.

For aftermarket starters, Arrowhead were half the price of oem down here and is a brand used by local bike shops. I paid about $400-$500 AUD. There are no name starters cheaper by half again but probably not trustworthy.

I'm concerned about that oil sludge.  Water entrapment or metal particles can sludge up the oil to make a paste.

Tomorrow I'll put in a new stator, aftermarket ElectroSport, same shop and brand as last year. I'll arrange the rubber gromet differently. This installation allowed water in, but not out.

The new stator gave the same 0.6 between yellows as the burned one.

OEM Denzo used, but working starter too.

Denso are usually very good.

1.500 revs; 19-20v on all three
2.000 revs; 27-29v on all three
4.000 revs; 50v on all three

Battery 1.500 revs; 13.6
Battery 3.000 revs; 14

Seven hours in a yoga position in front of my bike.

Starter, stator and new rear brake line. Easy enough?  [coffee]

That includes a new rear brake line. My wheel ate through the thing. Fiddly work. Done.

It also includes deciding, half way through, to cry/give up/try again when a couple of side cover bolts couldn't find their threads.  I might have used too little Threebond....  For sure I was clumsy putting the cover back on and touched/removed the grey stuff several times.

OIL LEAK  [bang] [bang]
This was when I stepped back and had to decide if I could believe that someone would show up and do the work for me. Or do it again myself. This second time one of the bolts got hold of threads again, I used more Threebond and put the cover on neatly. I haven't started it again yet, but there is no dripping oil. For now.

Crossing fingers for the starter to hold and for the oil to stay in the engine. I'll have the mechanic use proper Timesert next time (they just used longer bolts)(not good enough). Maybe I'll do it myself....

(https://i.postimg.cc/X7T3gNFx/20240718_123243.jpg) (https://postimg.cc/VdB3f8Kb)

(https://i.postimg.cc/P5YHVGQH/20240718_124217.jpg) (https://postimg.cc/gxz1rT7t)

(https://i.postimg.cc/fT3DXS3J/20240718_125209.jpg) (https://postimg.cc/8jV2g5mS)

(https://i.postimg.cc/J0F8vMFr/20240718_130637.jpg) (https://postimg.cc/dZGgTPvp)

(https://i.postimg.cc/cJWSVDFn/20240718_141008.jpg) (https://postimg.cc/5XsTzmd4)

 [thumbsup] [beer]

Looking good [thumbsup]