2002 Yzf426 fouling plugs like nuts

I was wondering if this was commin cuz it seem to do it alot and it is starting to get $. kills plugs to point i cant clean them off


do you start your bike and not let it get up to full operating temp a lot

if you start it you gotta let it run a little and get hot enough otherwise you will foule a plug pretty quick

are you cleaning your plugs when they foul and putting them back in??

if so how do you clean them, DO NOT by any means sand blast them and reuse it that is a bad idea

no i take a wire brush to it i think when it blows it fries the electrode all the way though but my buddys bike does the same thing just keeps fouling plugs

Mine was doing this also, do the BK mod! stopped mine... Correct jetting and the bk mod My bike runs killer and has 8 hours on the plug.

search for bk mod

8 hrs ? only that F^^^ it that the normal plug time ?

before the bk mod my bike would foul a plug in 2-4 hours of ride time. My current plug has 8 hours on it and still runs great, I have no plans on changing the plug and im sure Ill get more hours out of it.

ahh ic well thanks for the info hopefully i get my problem fixed

ill tell you wut i come out with

would adding a pipe and not jetting it be the problem to ?

I did the BK mod, set the timing correctly and I've been on the same plug for the whole of the 2006 racing season.

They will last if you warm up the bike and do the carb mod. Before I did it I'd flood the bike just thinking of touching the throttle.


lol that could be my problem never letting the bike warm up never realy did thank for the info

As stated do the BK mod. Stock the acc pump has over a 3 second spray time and with the mod you can get it down to under a second. If you need instructions go here.


My 01' used to foul plugs, but it was because i would start it, run it for like 1 minute then turn it off. When I started making sure it got up to full temp before shutting it off for the day then the plugs started lasting months and months.

Don't overlook the valve clearance. I had a tight center intake valve that caused me to foul a couple plugs on start up. I reshimmed the valve and all the problems went away.

running rich?

Do you have it jetted correctly, I have about 15 hrs. on mine with no problems. starts easily.

well i got too many on mine i use for trail and that other fun stuff

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