400ex sparkplug trouble

[ToothDoc]

03' 400ex K-n-N airfilter e-series White Brothers exhaust every thing else stock/Hard to start /some backfiring/spark plug is very black and dry/what do I need to do to fix this problem?Too rich?Too lean? What?

[quadrider400]

Must have more information....

Have you tried just putting in a different plug?

Try not using the choke.... If you have the whites and K&N have you done any rejetting?
How many disks are in place?

:confused:

[01 400EXer]

Sounds like the plug is carbon foulded from running rich. Put a new plug in and see what happens and then let us know if it still runs the same and then we can go from there.