Stator readings for a 12v AC system

[wilhets]

Hi,
Does anyone know what the stator readings are supposed to be on a 12v AC stator (6 pole)?

I've got a 100 sport with the electrical system from a pk125: stator, cdi, regulator, loom.

I'm getting 111.3 ohms on the red to wire, and 468-471 green to white.

Cheers,

[jbcollier]

www.scooterhelp.com/serial/service.V5A1T.V5B3T.VMA2T.html

Specifically:

www.scooterhelp.com/manuals/service.V5A1T.V5B3T.VMA2T/21.jpg
www.scooterhelp.com/manuals/service.V5A1T.V5B3T.VMA2T/22.jpg


Red/white = 110 +/- 5 ohms
Green/white = 500 +/- 20 ohms

You seem good on the R/W and pretty close on the G/W. What's the issue?

[wilhets]

Nice one. Thanks.
I've had a bit of an ongoing issue for a while. It'll run On most of the time, but every so often it will just die after riding it for a while and I'm struggle to restart it.

Stick a new spark plug in and it'll start first time. But then, after a few journeys, the same will happen again.

I'm trying to rule things out, one at a time.

The magnets on the flywheel seem OK, and will hold a 17mm spanner without dropping it. I've swapped out the cdi for the one in my ets and it seems OK.

I'm thinking maybe the reading for the lt coil is a bit low, and maybe it's causing a week spark as the cdi gets hot or something.

Would this cause the symptoms I'm having?

Cheers,

[jbcollier]

What brand and type of spark plugs are you using? Where are you located?

[wilhets]

I've been using NGK B6HS generally. They have been looking a bit glassy when I take them out when it conks out.

The last one I put in was a BR7HS. At the moment it's looking a nice coffee colour.

I live in Brighton.

Cheers,

[tzsteve]

Nice place Brighton
I lived ther in the mid 70's

I remember it being full of antique shops, gays and squatters

I think a couple of our more experienced members live down there

[jbcollier]

Just for the sake of ruling one more thing out, try a different brand of plug. Say Bosch or Champion. Or, fit an NGK iridium version.

I have several times had the same problem you are having solved bt switching to Bosch plugs or iridium NGKs.

[wilhets]

Oct 5, 2020 10:47:12 GMT tzsteve said:

Nice place Brighton
I lived ther in the mid 70's

I remember it being full of antique shops, gays and squatters

I think a couple of our more experienced members live down there

Wouldn't have it any other way. ;o)

Thanks for the suggestion jbcollier, I'll get a Bosch plug as backup. I'll see how long the current, slightly cooler plug lasts and go from there.

I was planning to check the timing with a strobe this weekend as well. Just to make sure the timing is even at higher revs.

Cheers,

[nickj]

I once had a problem with the pickup on the stator that would fail once it got warm due to a bad connection. It would cut out and not restart until it had cooled down. You could check impedance when hot and it has cut out to see whether they are consistent

[wilhets]

Good idea. I'll stick the multi meter in the glove box and give it a go.

[wilhets]

Hi,
Just getting back to this after I don't know how long.

I checked the timing with a strobe a while back. The timing was about 26° BTDC (ie about 8° to advanced). I reset it to 21°, which is as close to the recommended 18° as the cut out in the stator plate would allow.

I've run it a few times, and although it runs ok, I still get the same problem. It runs fine at first but then dies sometimes after a while abs struggles to restart.

I bought one of these ignition spark testers, which allows you to test his strong your spark is by making a spark jump across a variable gap.

The spark is supposed to be able to jump about 6mm. The spark on my 100 sport can only reliably jump a gap of about 2mm.

I tried it on my ETS and can get a spark of about 10mm, which suggests the tester is ok.

This seems to confirm that I've got a weak (or unreliable) spark.

Any suggestions as to what might cause a weak spark?

The stator coil readings all seemed OK, the magnets on the flywheel can hold a 17mm spanner (but not quite a 19mm).

Any suggestions would be great.

Cheers,

Wil

[jbcollier]

If the stator readings are fine, try another CDI box.

[wilhets]

Thanks jbcollier. I've changed it a couple of times over the years and it hasn't made much difference, but I guess it's worth a shot.

I'll see if swapping out the one from my ETS makes any difference.

Cheers,

[wilhets]

Bit of an update:
I swapped the cdi out, for the one from my ETS. Still only getting a spark of around 3mm (should be 6mm,had 10mm on the ETS).

I did a few checks on the electrics. Output and pick up readings seem OK. The only one that might need a bit more investigating is the green wire to the ignition switch to earth. I'm getting 1.1ohms in the OFF position and 0 in the ON position. I think it should be the other way round, right?

I'll have a bit more of an investigate there.

Other than that, I'm wondering if the flywheel magnetism is just a little low.

Cheers,

I'll

[jbcollier]

Do you mean "0" as in open? Or "0" as in a direct short to ground?

[wilhets]

I mean 0, as in 0 ohms reading. I'm not great with multimeters but my interpretation is that it is an open circuit.

My understanding is that the multimeter should read 0 with the key in the OFF position and infinite (or more than 20M ohms) with the key in the ON position.

I seem to be getting 0 in the ON position and 1.2 ohms (or something) in the OFF position. I'm wondering if the ignition switch is faulty, or maybe the wiring is dodgy.

Any ideas what to look for?

I hate fiddling with the wiring. Plus it's all pretty tight in the headset in the 100 sport and none of the original wiring is in there. /

Cheers,

[henri]

your ignition switch is basically a switched earth , key operated kill switch , with switch off ,as in scooter not running, you should get a 1-2 ohm reading .with key in the on,scooter running ,a "0" or infinite ohm reading ,pretty much what your getting .if still doubting your switch/loom ,disconnect the green killwire down at engine an see if problem goes away ,you'll have to stall the engine to stop it .
you say a 17mm spanner will stick to fly ,just, but it wont hold a 19mm ,that suggests its down on magnetism to me . a reading off 470 is low on a original stator , should be more 500 . but indian stators can be 460+ new ,an if lt coils replaced even the ducatti ones can read 470-480 new out the box .
as you know i live in brighton ,weve met, if you want a 2nd opinion on it give us a call .H

[wilhets]

Thanks H. That makes sense.

I was starting to think it could be flywheel magnetism. The lights and electrics are quite weak as well, always have been, but someone had changed all the electrics around before I got it, so I thought they might have been weak because of that.

I'll see if I can find out how much it'll cost to get it remagnetized. Otherwise, I guess it'll be about £70 for a new one (if I San find one).

I'll give you a call.

Cheers,

[henri]

you wont find anyone who will re-magnetise a electronic flywheel , least i never have , points flywheels yes , i resorted to making my own magnetizer but not 100% sure it works .i can give you tips on were a smalltaper fly can be got ,but they all need fettling before fitting .H

[tzsteve]

im curious about no one re-magnetizing electronic flywheels.
surely they are all magnetised after assembly.

so what`s the problem@ id really like to know what the problem is

come on input from the panel on this please