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

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • By Bgringo
      I've read a lot of threads about this but still haven't found exactly what I'm looking for.  I'm pulling my 2004 DRZ400S out of storage sometime this week and getting it ready for the season.  I live at 9,000 ft, but my first ride of the year is probably going to be at around 5,000 ft.  I was going to pull the 145 main jet I'm running and put in the 150 adjusting the needle from the 2 clip to the 3rd, then re-jet once I got home.  I already have the extended fuel mixture screw in place so I started thinking that I should just run the 150 jet set up and adjust the fuel screw to compensate for the higher elevation where I'll be doing most of my riding.  I will be going down in elevation for rides until late May or June depending on snowfall, but riding on the street when I'm able.  Are there any disadvantages with this?
      I'm new to posting on this forum, so please forgive me if I didn't get the right search words in and there is already a post about this.
    • By Markl5557
      I am currently running 10w 40 Belray non synthetic and I want to switch to full synthetic amsoil .... is it ok to switch from regular to synthetic? I have read it’s not safe to go from synthetic to regular can someone explain if it’s safe to go from regular to synthetic!? Thanks !
    • By RockyMtnMark
      Good Morning,
        Last night I measured my valve clearances for the very first time (I know...) on my DRZ400S.  It's a 2002 and I've owned is since 2011.  I bought it with t's got about 15,000 miles on it and most of it's miles these days are on dirt.
      Intake specs are 0.10-0.20 mm.  Exhaust specs are 0.20-0.30
      My intake valve clearances are in spec, forgot to write them down.  My exhaust valve clearances are between 0.1778 and 0.2032 which is slightly out of spec.  They are no more than 25 microns out of spec.  My question is, do I really need to shim these?  Will this kind of out-of-spec cause performance, mechanical, or other losses?  As far as I can tell, I'd have to buy a whole shim kit which is like $80.  Thanks!
    • By Zach440
      Selling my 2009 Drz400sm. Been a great bike but it’s time to let go . Not looking for any trades - spring is just around the corner ! Located in northern Virginia . Cash only $4200- willing to negotiate I have some wolfman luggage options available as well. Love to make a package deal for someone 

      -11640 miles . Mild off-road never wrecked.
      -Oil / filter changed every 1500 miles
      -New did chain , brake pads , front sprocket at 10400 miles .
      - valves checked and within spec at 10,000
      - jetted with JD kit and 3x3 mod
      -doubletake mirrors
      -waterproof usb wired and located next to Speedo
      - drc large foot pegs , barkbusters with integrated turn signals . 12oclocklabs tall delete with upgraded circuit board
      -thumpertalk case savers
      -sergeant seat (amazing) and Clarke 3.9 tank (190mile range )
      - fog lights wired in so they shut off with high beams
      -Shorai lithium battery
      -led headlight

      - stock gas tank and seat will be included

      The bike is dirty in photos and I apologize my water is currently disabled outside due to freezing temps . Radiator guards and skid plate NOT included but can be for some extra $$. Rear tire could be replaced but front is fine .
    • By tplayer100
      Currently have a 2000 drz400s work stock suspension. From my understanding this is the worst suspension the drz ever came with without even rebound damping adjustment. Therefore I'm looking for a upgrade. I'm seeing three approaches to take. First being a newer year s model suspension with dampening adjustment. A SM model USD forks and triple tree or some USD forks and triple tree from a rmz. So if you were going to upgrade what direction would you go. I currently ride off-road mostly but I do have some 17s for on road with as well so have to keep that in mind. Thanks