fouling plug

[7OahuEx]

Having a problem with plug fouling. I have a pretty stock 03 400ex, white bros rev-box e-series slip on w 14 plates. I ride with cr and kx 250's so i'm riding pretty hard and fast but if i slow down and cruise for a day the plug is fouled by the next day. I'm still running the stock NGK plug, just replacing it about every 2 to 3 months. Any thoughts would be appreciated.

Ride Red:devil:

[Rico]

Do you use the choke when you start it??? IF so quit...

[m1ke]

Possibilities:

plug needs regapping
rev box issue
fuel A/F screw need adjust
oil/carbon fouled
weak coil
wrong heat range plug
jet/carb issue (float stuck, wrong jet, needle seat worn?)

do you have problems starting?

[7OahuEx]

I ride on the weekends so it's always the first start of the weekends that it gives me trouble.(cold )

After it seems fine until the first start of the next weekend.

Thanks for the responses and I'll try starting without the choke also.

[Crazy Diamond]

Mine won't even start without the choke. And if I don't let it in the #2 position for a minute then let it warm up it fouls a plug! Not right then but the next time I start it.

[m1ke]

Yes these engines are like a 2 stroke it seems. And getting at the plug when shes hot :o :huh :ermm: or even getting at the plug on a good day :rolleyes:

[7OahuEx]

Yeah, tried to start without choke,---no dice---



As soon as i put the choke on it started after 2 tries.

Are any of you using a rev-box with the stock engine?

Any spark plug heat range changes.?

With the slip on e-series and 14 plates with the stock rev box, there were never any problems.

I Don't think of this as a major problem just a pain, having to carry extra plugs.

Thanks for your replies hope to have some updated photos soon.

Thanks,