Bayou 400 no spark, no 12v at ignition coil

[Ailll1 0]

I’m working on a Kawasaki Bayou KLF400 for a family member that doesn’t have spark. I’ve already replace the ignition switch and the stator which were defective. The stator had a melted connector and one of the phase had low resistance and low VAC output. 

What I’ve figured out so far is that I’m not getting 12V to the ignition coil when I turn the key to the ON position. From what I understand, the 12V should come from the CDI. I’ve resistance tested both wires going from the CDI to the ignition coil (Green/white and black/yellow). They are fine. The only 12V coming from the ECU is on the yellow/red wire.

I don’t have the wiring diagram for the 400 but I’m working with the one for the Bayou 300 which looks pretty similar except for the wire color between the CDI and ignition coil. On the 300 diagram, the yellow/red wire goes to the ignition coil, not the black/yellow… All the other wires color match except for this one. Not sure if that’s normal?

Thanks!

[Ajmboy 514]

 

In this manual, it shows:

[Ailll1 0]

Alright so wiring is correct.

So that means I should get 12VDC from the green/white wire coming out of the ignitor? I don't. Would that point to the igniter being the probrem? There 12V coming into the igniter from the ignition switch (yellow/red wire)
 

[Tom Bauer 1]

No, definitely not. There is no measurable voltage to coil on a CDI system and you can damage things by trying to test stuff incorrectly. A CDI cannot be tested by most people. By this I mean you need a very exclusive CDI tester, There are probably just a handful in the world. Use the service manual to measure the resistance of parts that feed the CDI, in this case it is only the pickup coil, if they are good, CDI is bad.

[Goingforbroke250 0]

Hate to question you Tom, but I’ve been reading thread after thread on this issue, and everyone is saying there should be 12v on the green/white wire. 
  I’ve got a single spark issue. It sparks when I have 12v on the green wire, but doesn’t when I lose the 12 volts, but it comes back if left disconnected for 5-10 seconds. Checked every ground, jumped things out, hate replacing parts because it doesn’t seem to have helped anybody except one I’ve read about. 
  Regarding that wiring diagram above, could someone post something more complete? 2nd post. Gonna be hard to hit 10 posts any time soon without spamming something with pointless messages... 

[IzzieGirl 1]

 so I just got a95 klf400. Same issue. The guy had replaced stator coil and CDI. We did continuity tests on the starting/charging system, and found that in the wiring harness, on the frame below the seat, there's a crimped connection with 3 wires splicing into 1. One of the wires was loose, and therefore not getting a good connection. A lot of frustration on my part, a very patient husband, and dab of solder later she fired right up. My hubby also found this problem in several places on his uncle's Yamaha. 

Edited June 6 by IzzieGirl

[Savage3 0]

The CDI can be tested for a short by checking continuity between the 2 ground pins (if it is a 6 prong) and the other pins. 

If you have continuity, the coil in CDI has a short.

Also, check the trigger coil, both of you....

[Tom Bauer 1]

CDIs cannot be tested by any conventional means. If it has 12 volts at the coil it is not a CDI system anyway. May be TCI.

[Savage3 0]

I built them for 12 years and they can be tested. The choice is yours, follow simple instructions and you will be fine.

[Tom Bauer 1]

All I am saying is that it is not a CDI system. I design and build CDIs

[Savage3 0]

I agree based on the information provided. It does not appear to be a CDI issue. More then likely trigger ir short.

[Tom Bauer 1]

No, I am saying that this machine does not have a CDI ignition system. It helps diagnose if you know what you have.

[Savage3 0]

Not sure Boss, the manual listed above clearly shows a CDI. No time to investigate...

[Savage3 0]

Ok, so the G/W wire goes to primary side of coil. Answer to the original post is.....yes. Once again, I would check for continuity between the two ground pins and the other 4 pins to verify short in CDI  before replacement. 

Edited June 6 by Savage3
More details

[Savage3 0]

Remember,  as Tom specified, a regular dvom cannot detect insulation breakdown under high voltage.

The test I recommended only identifies a short within CDI.

Basically,  if you have power at yellow and red and your coil has specified resistance (listed in manual) THE CDI is bad. 

In short, if components on either side of CDI are good and no spark,  CDI is at fault.

[Savage3 0]

Try disconnecting kill wire from CDI and see if you have spark, helps identify short farther up the circuit. No spark requires a good understanding and plenty of circuit testing before buying parts.

[MarkinAR 131]

Love the intelligent banter above on CDI's.  For a simpleton like me, I'll distill it down:  If everything else tests good, it's a bad CDI.  There's no at home test for an average DIY guy like me to conclusively test a CDI....so all things ruled out, it only leaves one option.

Occam's Razor, if you will.

Edited June 7 by MarkinAR

[Goingforbroke250 0]

On 6/6/2021 at 11:16 AM, Savage3 said:

The CDI can be tested for a short by checking continuity between the 2 ground pins (if it is a 6 prong) and the other pins. 

If you have continuity, the coil in CDI has a short.

Also, check the trigger coil, both of you....

What voltage should be coming out of each leg of the stator? Also what kind of reading should I be getting from the pickup coil as I rotate the engine??