Plug Fouling!!!

2 replies to this topic
  • Roger_H

Posted August 12, 2002 - 09:32 PM


THis is driving me crazy. My 99 WR400 has ran flawlessly until recently. It acted like a plug was about to foul and then got worse until it would not run. Changed the plug and it would run for a few minutes and start spitting and popping. Changed plug again and it ran fine for a few minutes and started the same thing again. I traced all leads I could with an OHM meter and found the plug cap had resistance. Pulled the resistor out and streched the spring to take up the slack and it runs great but files a plug at least every time I ride it. I change the plug and it runs fine until I put it up and then come back to ride another day..Any ideas???

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  • Dodger

Posted August 12, 2002 - 09:57 PM


I know it's seems odd for your jetting to become a problem all of a sudden, but it would be helpful to see what your carb settings are, and elevation, temp, an so on. Have you cleaned the carb lately?? Any idea if an air leak appeared from no where???

Let us know, and we can go from there.

Dodger :) :D

  • mikeolichney

Posted August 12, 2002 - 10:59 AM


There is a good chance you have bad gas. No, not the rolaids kind. Several of us here in CO have had the plug fouling problems due to using oxygenated 10% ethanol gas that is mandated here in the winter.

Try draining your tank and putting in gas you are sure is OK (buy some race gas to test this if unsure).


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