I can only get one hour out of a plug......

['00KX250er]

My '00 kx250 fouls the plug after about one hour of riding. I can take it out and it is black with fuel all over it. I was running a NGK(that is what it had in it when I bought it). I had to go to the local autozone and get some champion copper 805c/n2c.

My premix is one pint of Klotz BeNOL to 4 gal. of 93 octane.

These are the some of the causes I think.....
It needs a new air filter(it's not dirty, just old/ratty)

The carb leaks fuel from the bowl gasket and needs to be rebuilt/retuned.

I'm sure it needs a new piston,rings,etc, I'm not sure if it has ever been changed/inspected. Cylinder may be scored to hell...

I'm not sure what the reeds are like, I was going to go with a v-force soon.

Overall the bike runs strong to be stock. I plan to install a new filter, replace top end(if that is all it needs), go with a v-force valve....

Any opinions?

 

[ellandoh]

do it before its too late

 

[MXSparx]

You need to get the engine in good working condition before you can get the jetting squared away. Once you've corrected the obvious things that you mentioned, it will be alot easier.

 

['00KX250er]

Yeah, I'm waiting on the service manual to get started.....

 

[john stu]

i wouldnt put a champion spark plug in my lawnmower they suck! get an ngk,nd,or anything else!

 

[Crash 142]

Check the float level. The carb leaks from the bowl gasket, or the gas comes out the overflow? Sounds to me like your float is way off, which is the same problem I had with a 95 KX 250 I had long ago.

 

[bikepilot]

Get the carb squared away then get the jetting right. Also, use a BR8EG or BR8EIX plug. The floats are probably stuck causing fuel to dump into the cylinder. Also, don't ride it untill you get that air filter fixed as you are probably sucking in a bit of dust (the pores in filters get larger with age and oil gets less sticky).

good luck

 

[DirtIsMyName]

Temperature keeps the plug clean. It will run too cool for any of the reasons mentioned in this thread or any combination of them. Start with compression.

 

[xERICx]

Make sure none of the carb vent hoses are clogged.

 

['00KX250er]

Cool, thanks for the tips guys. That plug was my only option at the time, I was trying to teach a buddy how to ride a bike like this, he loved it. I hope to have the manual this week and see how the cylinder looks.....