Spark plug problems

Hello fellow wr owners. First of all Im very glad to have found this forum! Im a swedish guy who recently got my hands on a 2001 wr 426. Im a typical newbee and my questions may be dumb but I still hope someone will take some time and try to help out. =)

My problem this far getting the bike started. The first times it went well and one kick was enough to get it started. I reved it some and warmed up the engine but I did not ride the bike ( I live in a city). Next time it wouldnt start at all. There was nothing. I removed the spark plug and it was very black and dirty. Cleaned it up and put it back there and got the engine runing again. The next day it was all the same...couldnt get it starded. Cleaned the sparkplug and started it again. Im not sure but is this what you guys refer to as "fouling" a spark plug? In that case....whats up with my bike? I will get a new spark plug and see if it works.

As I said I havent really ridden the bike so i asume the fuel mixture is pretty rich at those rpms.

Also...I read at motoman's site about pulling out the lightblue cable to get a stronger spark. My question is then....could this damage my bike in any way? What does this blue cable do exactly?


Yep that is a fouled plug for sure!,one thing i have noticed with the 01-426 is that they do not like to be started up and not ridden,i dont think the plug gets a chance to come up to the right temp to keep it clean!,black sooty plug is caused by too much fuel,you said it did spark again when you cleaned it so it may have been fould by one of two reasons,#1 your jetting is rich on the pilot or fuel screw range or#2 your accellerator pump is not set up good!(it may be pumping in too much fuel),you been reving the bike up once you start it up!,is your bike a euro model?,i don`t think the wire mod needs to be done on them?,check out the carb and see what jets and needle are installed in the carb,make sure you have a clean air filter?,you can also use the search feature on TT to look up old info on the bike,IE:blue wire mod or accellerator pump mod(bk mod),also post the altitude you ride at,the temp and your weather,it help folk to get an idea of what your conditions are,you may want to try the jetting forum too,also welcome to thumpertalk martin,you are now in the right place to get it sorted! :thumbsup:

Ok! I have now installed a new sparkplug and it started instantly. I believe my problem was that simple =) Sorry bout that =)

I think if it the engine only gets warm there is no problem with fouling. Ill get back when I have tried the bike where it belongs!



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