400ex spark plug trouble

[ToothDoc]

O.K. Got new 400ex and broke in a few months ago.Ran great.then place K-n-N air filter and e-series White Brothers exhaust.After a few rides could not get to start so checked plug and it was black and dry.Which I thought it would be gray or white due to being to lean.So placed new plug and after a few rides the same thing happened again .It seems to run fine ,a few backfires here and there,but no real problems except for starting .It seems to run fine after I clean the plug.Can someone help,I'm sure this is the first time this has happened.white Brothers states this pipe is for stock jet settings and no rejetting needs to be done.

[JOEX]

That seems odd....:confused:

I bought mine used with the K&N, WB E-Series and a 150 main jet. I never had much of a problemn getting it started. I even went over a year with the same plug. But I don't get to ride a whole lot either.

Joe

[400exride.red]

kinda from way out in left field here any chance ya left da choke on??
just a thought ?

[cals400ex]

are you running stock jetting?? also, are you checking the plug after riding or before the next ride??