Strange CDI glitch

[dANbOT]

I'm having some strange problems, I'll start at the beginning...

A short while ago, I was stranded in the bush with no spark on my 2014 XC300RE. While digging through wiring looking for the problem, the red wire came out of the CDI connector so I soldered it back onto the pin. I think it was still connected, but ready to pull apart, but could find no other problems so put it all back together.
The bike ran fine after this for a few rides, but stranded me again with intermittent spark. This time, if i grabbed the stator wiring leading up under the fuel tank, I could get the spark to come, and go. This time I tested the entire harness for continuity, and made sure all the tiny pins in the CDI connector were tight. To my disappointment, it still did not start.
I started wiggling the CDI connector and harness, and had spark again. With the bike idling, I could wiggle the wiring / box and it would cut in and out.
After throwing a spare spark plug in the boot, I noticed that wiggling things in that area with the key on / ENGINE NOT RUNNING, I was getting spark!?

Here's a video, anyone have an idea? I'm thinking toasted CDI shorting internally and triggering the coil, but I'm in WAY over my head haha

https://www.youtube.com/watch?v=cPBO...ature=youtu.be


Thinking ahead, I only see older style CDI's and one 2015 unit (different colored wires in the connector) on ebay. I'm assuming the days of installing RM125 CDI's are gone with the multi-pin connectors, and batterey powered CDI on my 2014?

[dANbOT]

BUMP

Really hoping to figure this out so I can start trying to source parts ASAP!

[Neil E.]

I can see from the 2014 wiring diagrams in the owner's manual that the estart and kickstart bikes are handled differently. Both use the same AC-DC rectifier. The estart charges a battery, the kickstart charges a condensor (capacitor) as far as I can tell. Neither system uses the stator single winding that was the normal method on all the older bikes.

Both the 2014 CDIs are connected differently and may have different part numbers. The kickstart bike grounds 48 at the CDI to stop the engine. The estart bike grounds the trigger output 56 to stop the engine.

Based on your video I'd say that you have a bad connection that is telling the CDI to discharge. It's acting like you're making a connection to the trigger input and that is why it sparks.

I don't know how the trigger (pulser) actually works. I expect it functions like an inductive sensor that turns on when the flywheel bump passes the trigger. To me this would be a closure of an internal circuit in the CDI, but does it pass a voltage to work?

Can you separate out enough wires to determine which one makes the problem occur?

[dANbOT]

Thanks for the reply

So far I have determined that with the key switch on, power is supplied to the CDI through a red wire, once that power is on... it will do the random sparking thing if I jiggle the CDI box.
-no difference if the stator /pickup coil wiring is connected or not
-if I unplug the coil trigger wire and test for 12v+ while jiggling the CDI I get some very strange sweeps on the tester needle from negative voltage to about +6v if I recall correctly
-All wiring in the harness shows clean continuity, and has no visual damage. I payed special attention to the group of wires that lead to the stator connector (which is where the pickup coil signal must come from)

I'll be digging in again, but i just can't wrap my head around how for example a shorting, or broken wire could trigger the CDI to fire so rapidly.
Today I will completely strip the wiring and continue looking for a problem, I don't expect to find anything as I have been through it all already.

Through a north american distributor for JD Racing, I see a unit for my bike for $550 USD, that's going to translate to at least $700 by the time I got in to Canada with the exchange rate and shipping. I'm sure hoping someone chimes up with another option like a KTM CDI or the old RM125 units guys used to install on the older Gassers. This is starting to feel like it will ruin my summer.

[Neil E.]

I feel your pain. About the only thing I can think of is to see if you can get the individual pins out of the CDI wiring harness connector except for the red and the ground, then put the others in one at a time while jiggling. If you could track the issue to one specific wire, that might show if the problem is with the wiring harness connector.

Next would be checking the CDI connector by opening the housing and looking for a bad solder joint at the connector pins. It sounds like you have a bad CDI unit, but it sure would be nice to know before spending that kind of money.

If you had access to a (cheap) older CDI, you could convert your bike to work the old way using the existing single winding on the stator. I assume the pickup is still the same. The wiring diagrams are good enough to compare old and new systems to figure out what wires to put in the connector pins. This also assumes the connectors are the same between old and new CDIs with just the wires moved to different pins.

[dANbOT]

I spent the a good part of today checking the wiring / connections very carefully. I didn't really find anything so I squished the ecu connector pin sockets to make a tighter fit, not that they were overly loose.
Now the bike seems to be running fine! I have a hard time imagining loose / crappy pin connections making the coil do what it was doing, but it seems alright.
I went for a 4 hour test ride and had no problems, going to try and ride uphill only for a bit to let it prove itself.... crazy haha

[dANbOT]

Just realized I never came back to report. Bike has been running great since tightening the CDI pin fit. Crazy what a dirty connection can do.

[CombatYoga]

I have been having the exact same issue Danbot!

Intermittently quitting - had to recover my bike twice over the last 2 weeks when it quit on a trail.

I debugged it today with my mechanic - he had one of those lights that shows when a signal goes to the spark plug. We could intermittently lose spark altogether, and on other occasions the timing would be way off and the bike would back fire.

We read your post and took the same steps - bent the metal tabs in the connector to tighten things up. It seems to have worked as we jiggled wires and tapped it with a mallet while the bike was running and it seemed to hold up.

I am going to try to ride tomorrow or Wednesday to see if I have any more problems.

I'm leaving Wed. night to race in the Tennessee Knockout Enduro - I'll be gutted if the bike quits on me during that contest!

Thanks for posting your experience - it helped us!

[dANbOT]

I hope you got it!
Was the rubber strap that's supposed to hold the CDI still broken on yours? I always felt that this was the root cause of my problem.

[CombatYoga]

That broke a while back and I had zip tied it.

This time I used 2 horizontal zipties and put a piece of foam dampening material between the CDI and the frame. As I sit here and think about it, I wonder if I should put 1 or 2 zip ties VERTICALLY to firmly hold the plug into the CDI?