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Goosedog

Heat related issue with my '02 426

45 posts in this topic

Got a chance to take a long ride yesterday and experienced a symptom I thought had been cured. After my bike's good and hot from woods riding (this won't happen at the track with shorter laps and more breaks) it starts to cut in and out at low steady RPMs.

I had this issue narrowed down to being electrical last fall realizing jetting or valves would not be heat related. So I put in a new stator, checked the coil and plug boot and thought the problem was solved but hadn't gone on any lengthy rides til yesterday.

This is something that only started last year so I know it's a part that's failing and not something that better antifreeze or engine oil can fix so please spare me those sales pitches.

I'm almost convinced it's gotta be the CDI box but my mechanic says they can't really be checked. I'm wondering if it can be sent somewhere to be tested.

Anyone else have these problems or a good guess as to what might be the fix?

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The coil would be more apt to be at fault than the CDI. ECM's usually fail completely rather than a soft, or intermittent failure. It can happen, though. If you can find known good components to substitute, try them each, one at a time.

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The coil would be more apt to be at fault than the CDI.

I took the coil down to the local shop and they OHM tested it right in front of me and it checked out to spec. Can they check out OK when cold but fail when hot?

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Yes, they can. The resistance can change with heat, and they can actually develop a break in the coil that will loose contact with heat. This last is less likely with modern coils, but still possible.

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Yes, they can. The resistance can change with heat, and they can actually develop a break in the coil that will loose contact with heat. This last is less likely with modern coils, but still possible.

Since a new coil is pretty cheap I may go ahead and get one before taking moto2000 up on his offer for the CDI. Is there an aftermarket or newer year model you'd recommend or should I stick with a stock '02 part?

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You can convert to the later style coil that is built into the plug boot. The YZ part can be used, and IIRC, one of the Suzuki GSX-R models interchanges. Don't know the details.

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Thanks Moto2000 and Fastest1 for sending me your used parts and input.

Right now what I'm concidering is the "coil in cap" upgrade from and R6 (need more info on this mod) and an aftermarket high performance CDI. Do you guys know anything about a Berg Racing Wolf CDI?

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I think the coil on cap is the way to go. I have Hayabusa coils on my 426's, but I'm not sure what other coils will work. Removing the standard coil cleans up the right side of the bike and makes carb work easier. I also shortened up the wiring harness and got rid of the excess clutter.

Whatever coil/cap you get make sure you get the wiring harness with it...other wise it's kinda hard to connect.

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I think the coil on cap is the way to go. I have Hayabusa coils on my 426's, but I'm not sure what other coils will work. Removing the standard coil cleans up the right side of the bike and makes carb work easier. I also shortened up the wiring harness and got rid of the excess clutter.

Whatever coil/cap you get make sure you get the wiring harness with it...other wise it's kinda hard to connect.

I've heard the Gixxer, R6 and now Busa coil/cap will work. Can one of you guys post a part number, picture and/or discription of the work.

This sounds like a great 426 up-date mod (almost up there with the 450 auto cam), I wonder why it's not better known.

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Actually we used to rant and rave about it but time has gone by. It really isnt a performance mod as much as a change to the unique for bored people in the garage late at night! BUT if you are going to change the coil anyway why not? All of the bikes mentioned run the same coil (GSXR, BUSA, R6) and they all will work. Is there a salvage yard in your area? It is an easily identifiable part. Someone here on TT has the whole set up I am sure. Sometimes people would buy all 4 from an Ebay auction and offer the other 3. Just remember DONT FORGET THE PIGTAIL. I can not stress how impossible that connector is to find and it cant be substituted well, if at all.

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Actually we used to rant and rave about it but time has gone by. It really isnt a performance mod as much as a change to the unique for bored people in the garage late at night! BUT if you are going to change the coil anyway why not? All of the bikes mentioned run the same coil (GSXR, BUSA, R6) and they all will work. Is there a salvage yard in your area? It is an easily identifiable part. Someone here on TT has the whole set up I am sure. Sometimes people would buy all 4 from an Ebay auction and offer the other 3. Just remember DONT FORGET THE PIGTAIL. I can not stress how impossible that connector is to find and it cant be substituted well, if at all.

Thanks for this and the PM Fastest1. You mention in the PM that I have to get the pigtail assembly salvage only. If I can't find used parts then could I not get just one (not all four) cap plus pigtail new from the parts store?

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The pigtail is probably not serviced except as a complete wiring harne$$, which you would not enjoy buying. GM sells generic connectors to repair most of the common ones used on their cars, but I don't think this practice has yet filtered down to the Moto industry. Considering the complexity of the wiring on a modern bike, it should.

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Ok, now I've got a better idea of what you guys are talking about. I went to the parts store and saw what the cap looks like and how that design necessitates the male plug with a little wire included to retro-fit to my YZ.

The salage yard I called said $100.:lol:

I do have a question though; it looks like the pig-tail coming off this new cap will have about three wires and on my YZ, there's only one wire coming from the CDI to the coil, how will that work?

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Actually there are 2 wires, 1 is ground and the other is the signal from the ignition. You went to a dealer and they would include the pigtail or did I just misunderstand you? I have never seen that pigtail offered (anywhere) and I live in Houston which does have a few sources for specialty parts. 100 is way to steep. Post on here for one and I can check a local salvage yard, I do have a few friends in that business. I will let you know.

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Actually there are 2 wires, 1 is ground and the other is the signal from the ignition. You went to a dealer and they would include the pigtail or did I just misunderstand you? I have never seen that pigtail offered (anywhere) and I live in Houston which does have a few sources for specialty parts. 100 is way to steep. Post on here for one and I can check a local salvage yard, I do have a few friends in that business. I will let you know.

The dealer would not include a pigtail but the salvage yard said they could. I agree $100 is way high, I'm gonna check ebay again tonight. If you find one please let me know. Thanks again, Goose

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