Black plug with FMF jetting specs?????

3 replies to this topic
  • dunecj2a

Posted August 05, 2005 - 09:42 PM


Alright fella's I don't mean to beat a dead horse but I need some advice on how to read my plug. I'm runnin a complete FMF Ti4 system with there power up jet kit. I also have the Boyssen quick shot pump cover. I have it jetted to FMF's/Dynojet kit recomendations. I live in Tucson so I figure the jetting specs would be real close to FMF :D

I pulled my plug out after a month of riding every week. It is really black,dark black but the very end of the electrode has a small white spot. Can't hardly notice it unless you look hard. I swapped it out with an Iridium plug and put one ride on it. When I pulled it out it was really black also, but the tip was clean. So whats goin on here, am I really rich? Whats up with the white tip???

  • mxaction

Posted August 06, 2005 - 02:54 PM


Yes, I would definitely say your running to rich. I live in Nevada, and every FMF exhaust I have installed on bikes I used the stock jetting with. Most of the time the PowerUp Jet Kit from FMF only comes when you purchase an ATV exhaust.

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  • Hick

Posted August 06, 2005 - 03:39 PM


Alright fella's I don't mean to beat a dead horse but I need some advice on how to read my plug.

Okay, here's my advice:

Don't bother reading your plug. Your bike has an accelerator pump that squirts an unatomized stream of gas into the intake every time you touch the throttle, and even if it didn't, or if you disabled it to do a plug check, you have no real way of telling which carb circuit is making the plug look the way it looks.

Of course, you could disable the pump and do a plug chop, but that seems like a last resort type of effort....

If you are interested in optimizing your jetting ignore what the plug looks like and jet it to run the best.

My two cents on plug reading...

Other than that I second McGill's opinion, but extend it to most every aftermarket exhaust. The stocker is pretty free-flowing, if you jet it to run w/ the stocker swapping to an aftermarket is not likely to require rejetting.

  • dunecj2a

Posted August 06, 2005 - 03:45 PM


Alright thanx :D Yeah it runs good so I'm not gonna mess with the jetting. I can live with a black plug!!!

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