I've got oscillogramms, now I need experts. what's going on?

Bike is not starting. So when I press starter the CDI sends a spark regularly 1 on 6 cam revolution when the battery is full charged and then it gets crazy when the battery is at about 11V and under (slower rev). Help me find out what's happening :D

High voltage coil, CDI to spark plug. battery full. We can clearly see the spark and it's more or less regularity.

Señal Bobina de alta bateria cargada.jpg
Here another example:
señal cdi.jpg

High voltage coil, CDI to spark plug, battery 11V. Irregular spark. We can totally see the missing sparks. Normal time interval seems to be 250ms.
señal bobina de alta bateria agotada.jpg

Source/Signal coil, looks alright to me
señal bobina de encendido.jpg

Pickup coil/Captor, looks alright to me
captor .jpg

Thanks a lot!!

Check gas?

If your battery is at 11v it's not fully charged.

Your battery should read 11v+ while cranking, then recover back to 12+ within a few seconds.

If it's dipping under 10.5v cranking, the battery is no good or needs a serious de-sulfation, if possible.

That COULD be a possible cause for no-start, but yours is more likely fuel or air related.

Sbmon, Mjruopp, thanks for answering. It is not fuel, nor air, nor battery problem. I explain. Problem is the spark. If there is no spark when there should be one, the engine makes one explosion and next turn nothing (fuel/air mix in the chamber and no combustion because no spark). I just talked about the battery because it is a factor that might be important to explain why the CDI sends more sparks and more irregularly than when the battery is full charged. My guess is that the CDI is dead. But I really wanna be sure! :)

CDI death is unlikely and very rare.  are you the guy that rewound his stator ?  if yes I think its your stator or the pick up incorrectly assembled. 


when troubleshooting always start w the last thing you touched or was worked on

Yes that's me! I rewound the pick up twice to be sure only to get the same result. Proof is the oscillogramm showing it's sending normal signals. Signal coil is fine aswell. What could cause the CDI to act this strange?

Boy it has been a long time since i looked at an ocilloscope reading.....but i don't see your secondary voltage.... only signal voltage.....secondary should be like 25kv

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