wr 426 eating plugs

i need help i have put a standard pipe off my yzf 426 onto my wr 426 and it eats spark plugs quite regulary i have tryed rejetting it and that has cured it slightally but it still eats them but not as often could anyone help me or give advice

mudie 426

When you say eats them , do you mean they just stop working or does the firing tip disappear? :ride::ride:


Disappear? :ride: lol! Yeah, that would be some pretty serious detonation.

Are your plugs fouling out, mudie426, and what's with the smiley?? (I know... Welcome on board. :ride: ) What is your current jetting? I assume you're near sea level... Any mods done to airbox too?

I went through a lot of plugs (fouled black and sooty) in the last 3 months as well. I was told by fellow TT'ers to pull the carby out and give it a good cleaning. I checked the Air cut valve, the accellerator pump, pulled all the jets out and blew compressed air through them. I also raised the clip on the needle to the #2 slot (counted down from the top) It was on the #5 position. By doing that it also gave me all the numbers of the jetting in my carby. Now when I have problems, I can quote exactly what my jetting is and what the problems are... It gives everyone else a better chance of helping me diagnose the problem... which by the way have disappeared after lowering the needle.

I am running a

Main 165s

Main Air Jet 200

Pilot Air Jet 75

Starter Jet 65

Pilot Jet 45

Needle OBDQR on the #2 position counted down from the top

Elevation is about 300 meters... temp right now is 30+ degrees C - Humidex of 40 degrees C :ride: HOT!!!!!!

Good luck :ride:


firstly i am right on the coast and thanks for the advice guys i duno about the smiley i thought i would just see what it about i am new on here lol the bike is just foulding the plugs to the point were it miss fires or dose not run (fouls them) every thing is just standard wr settings but i took the main jet down to a 160 and took the air box cover off once again thanks for adivce

try an iridium plug

Yeah, NGK's iridium CR8EIX works well. Check your pilot fuel screw setting too. It should be at about 1 1/4 turn out.


So the plugs are sooty black? If so, go down a couple more sizes...

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