YZF 426 no spark--- why?

My 2002 YZF 426 was running great the other day. Then I put on some new Moose handguards/barkbusters and a Moose skidplate. When I tried to start it up afterwards, it would only sputter for a second and then died. No amount of kicking would get it to restart. Thinking I had fouled the plug by moving the throttle back and forward during the handguard install, I replaced the spark plug. Still no run, at all. So I pulled the plug, and discovered that ow I am delivering no spark at all to the plug. I checked the kill switch to make sure it wasn't stuck closed; it is fine. All the other wires appear fine. I did nothing else. Any clues where to start? I am not very knowledgable about these machines yet...

Your new plug may have been dodgey try another new one and this time check it works before screwing it into the head.

Check all electrical connections first.

I have checked all the electrical conections that I can see, and they all look fine. I also tried a 2nd new spark plug, and I am checking it before I screw it into the head. No spark. The new plugs are CR7E's, and the plugs I have been running for the past 6 months are CR8E's. Could this be the problem? I think the bike had a CR7E in it when I bought it, but when I got my first replacements, the dealer told me the CR8E had replaced the CR7E. So that's what I have been running. Now I am in a new state, and the local dealer had CR7E's, so that is what I just got.

The plug with heat ranges that close are fine,at least enough to start it. Is your coil on the frame or in the cap? Check the coil next.

You mention that you installed handguards, is there any chance that you pinched the kill switch wire somewhere and it is grounding out? Also, on the coil there are two connections, a signal wire from the CDI and a ground wire. Make sure that you haven't pinched either one of these anywhere and that they are both clean and tight. Hope this helps.


You mention that you installed handguards, is there any chance that you pinched the kill switch wire somewhere and it is grounding out?
Very sharp, Josh :mad: I was wondering when that would come up.

I am an electronics technician by trade, I know the agony a pinched wire can cause. Thanks for the props Gray.


As a professional mechanic for so many years, something that I learned to do whenever something bad happened right after I worked on something was to ask, "What part of the failed system was I working near?" It's usually the quick way to figure it out.

Thanks everyone. I'll keep playing with it this weekend.

This is a long shot but has gotten me once. Check that the coil wire into the plug cap is all the way in and making contact. After that listen to Grayracer and jbrooks. These guys give good gouge.



Gouge? :mad:


Gouge = information as in at OCS we recorded all notes on "Gouge" pads, the little spiral bound notepads.

How you doing F1? Hope all is well with you.


Besides my understanding of the english language, everything is well with the entire family. Hopefully for you and yours also!


Family is great, I just had surgery #10 in June. Complications in the form of MRSA infections under the incision and the mesh is infected now. Other than these things I am okay:thumbsup:


Well, I traced all the wires. Nothing is pinched anywhere. The kill switch was examined in detail, nothing abnormal. The wires at the coil are connected and in good shape. The wires at the spark plug cap are good. Still no spark. I plugged the spark plug into the wire, and laid it against the side of the engine head so it was contacting the head. I can hand-crank the motor since there is no compression build-up with the spark plug out. I should be able to see spark at the plug using this method, correct?

The weird thing is, immediately after replacing the handguards, I tried to start it up and it sputtered and ran for a few seconds, then nothing. This tells me that the electrical system was working for at least a short period of time after the handguard install. Could my coil or CDI box have coincidentally conked out right then? That would be a little weird...

I am about ready to take it in to have a mechanic fix it...

If by some strange reason it was the CDI or coil, what should these cost?

Run a test on the coil and see if it is within specs. I wouldnt think the CDI or Coil would fry that way (though it could and it would be instant). BTW I think I have a coil for a 426 in my parts pile. The CDI would be more though I may have one of those also because I run a Vortex ignition. It is off of a 2000 so the curves might be different than other years but it would work.

In case anyone cared, my story has come to a happy ending. Turns out the stator fried out. New stator, everything works perfectly again. Why would the stator coincidentally go out right after puttng on new handguards and skid plate? Don't know, but it is working great now!

I care and congrats on the fix, happy riding.:worthy:

Why would the stator coincidentally go out right after puttng on new handguards and skid plate?
They quit when they want to. :worthy:

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