Diminishing output from CDI - 30 Volts to 2 Volts

[FlyingBlindOnARocket]

Originally Posted by carasdad

.1/.2Vac is arriving at the ignition coil?? Well we know that is not good and won't arc. Stator is down from 80V to 60v...odd. But it started to spark then stopped. Tells me something is shorted and burning a wind in the pickup or stator...possibly. Even a stator with only 60 volts will excite the coil and induce a spark. Weak yes..orange in color but it will be there. The only thing between your stator and Coil is the CDI. But you said you swapped CDI's so that rules out that the Electrolytic Capacitor in the CDI is bad. This sounds to me like a bad ground..or a short to ground from a hot wire. Usually the short to ground is found in the kill switch wire in the handlebar switch set or CDI itself (from my experience) Sad to say but my Dad was an Electronics Engineer and you got stuck with me.. The one who chose the Medical field vice the Mechanical or Electrical field. He did drill me hard as a kid on Watts..Amps..Volts..Current..Resistance..Ohms law and all that stuff. But still..we WILL figure this one out..
Glenn

I did get identical results from 2 different stator/ trigger coil combinations, and 2 different new CDIs today.
A few weeks ago I did remove the wiring harness (which was very wet at the time) and let it dry out, then put lengths of marine heat-shrink tubing around every splice. The factory splices were only wrapped with a bit of electrical tape, so it seemed there was room for improvement. Also, I added and additional ground wire from the CDI's ground wire directly to the frame.

My father was an electronics tech as well, he started on the in the Air Force then ended up repairing TVs and such.
Thanks for your help!

[FlyingBlindOnARocket]

I wanted to add 2 other things that may or may not have anything to do with this. Occaisionally, the fuse would blow when I tried to start the bike. either when the key was turned or the start button pushed, I don't know which. But once a new fuse was ut in, the problem was gone. The second is that 3 or 4 times the CDI would suddenly fail. Again, once replaced things would go back to normal. Each of these happened maybe 3 times over a 6 month period.
Both these things would happen without anything else going wrong.

[carasdad]

Originally Posted by FlyingBlindOnARocket

I wanted to add 2 other things that may or may not have anything to do with this. Occaisionally, the fuse would blow when I tried to start the bike. either when the key was turned or the start button pushed, I don't know which. But once a new fuse was ut in, the problem was gone. The second is that 3 or 4 times the CDI would suddenly fail. Again, once replaced things would go back to normal. Each of these happened maybe 3 times over a 6 month period.
Both these things would happen without anything else going wrong.

Classic sign of a bad ground or 'Sloppy loose short' My dad was an Electronics Tech in the Navy. I joined the Navy...only to find out after my recruiter lied(yes they do lie) I found out that Navy Corpsman become U.S. Marine Field Combat Medics. So next thing I know I am covered in Cammie face paint..wearing BDU's just outside of Kuwait..then later Iraq. We also did..and get this cause I think it is bullsh!t.. We did drug interdiction in Columbia. We set up a 180 degree perimeter..captured the Cartel..then were told to stand back. Guess who comes in and steals all the glory?? The DIA..Drug Enforcement Agency gets credit for what we did?.. Ok..Politics...in action I suppose..
Anyway..enough of that..back to your scoot.. If a CDI or fuse is failing or blowing..you got a definite short or bad ground.. Did your replace the stator? Or check and sand it's mounting area..as they do often create a bad ground..It is simple whatever it is..usually is..
Hohodika ela seyiimee dachamosan bela ieta sik Ojibwa tayatoola momonagi dadanemuk <-- I am a Chippewa,we were eradicated for being savages, not mechanics. lol.. But we will figure this out my brother of the earth..because.. Jiloho bena atika aya tiseemie moyat esesana aha kota <-- We only become defeated when...we stop trying to defeat something....

[FlyingBlindOnARocket]

Originally Posted by carasdad

Jiloho bena atika aya tiseemie moyat esesana aha kota <-- We only become defeated when...we stop trying to defeat something....

Which also translates as "A quitter never wins and a winner never quits".

A bad ground sounds likely, but where could it be? 2 stators are producing the same low voltage (60Vac). When I last tested it about a week ago it was putting out around 80Vac. I'll pull the stator tomorrow a give the contact areas a cleaning just to be sure, but up until this point there's been no problem with it.

So far, the CDI, Stator, Regulator, Trigger Coil, Ignition coil and Spark Plug have all been replaced with no change resulting other than getting a spark for a while after the last trigger coil replacement (That is, when a new one was put in, right now the stator and trigger coil that are installed were pulled from another bike).
The condition worsens over the course of a few seconds. The CDI's output starts at 20Vac and drops to 2.
I think we can probably eliminate the ignition components as the source of the problem.
That leaves...? The starter and ignition switches have been tested and showed that they were good. I checked the wiring harness visually and didn't notice anything wrong with it. The brake light switch? Something in the taillight? I think I might just end up replacing each part on it until it works!

[FlyingBlindOnARocket]

Ok, it's been a while but I've done some more work on it with no results. I replaced the stator/trigger coil with a brand new set as well as both handlebar switch sets. At this point the only electrical components that haven't been replace are the flasher and the starter motor.
Is it possible that the starter motor could be worn and not turning the engine fast enough to generate enough electricity?

[FlyingBlindOnARocket]

I just went out and tried starting the bike again after having harged the battery and I may have been on to something - The starter barely turned and gave a high pitched grinding/whirring sound. I'll dig up a new solenoid and try switching that out just because I have one, and I'll order a new starter just to cover that too.

[FlyingBlindOnARocket]

Put a new solenoid on it and there was no change. Ordered an new starter motor, it should arrive by Monday.