kx 250 fouling plugs

[tantheman125]

a freind of mine has been working on a 97 kx 250 and hes done everything trying to keep it from fouling plugs...hes changed the jetting the air adjustment im not sure what else but about every 2 miles it fouls a plug....just need to know what you think it could be... any suggestions would help

 

[76GMC1500]

2 miles of crusing and idling or 2 miles of balls to the wall?

 

[2strokerfun]

I've been fighting this for about six months and finally decided that I didn't get my main clutch side seal seated on the crankshaft right last time I split the cases. On a 10 year old bike, a bad clutch side crankshaft seal can cause this because it sucks up tranmission fluid into your engine as you are running. Look for loss of transmission oil, but in my case, I change my transmission oil so often, I've never noticed it was low.
Wrong float height can cause this, but unless someone bent your float or it leaks, it usually doesn't change settings much. Weak spark can also cause this, but my experience is my spark is usually strong enough or non-existent.
Most times, it is jetting. Keeping on the throttle will help minimize the problem, but won't fix it.

 

[Racesmith]

You can try increasing the fuel/oil ration... maybe start at 40:1

 

[rmc_olderthandirt]

You can try increasing the fuel/oil ration... maybe start at 40:1

I would think that plug fouling would be from having too much oil.

I think the first thing I would try would be to use a hotter plug so that it would burn off the deposits instead of letting them build up until the plug fouled.

What plug are you currently using?

Rod

 

[elcamino12sec]

Try a NGK B7ES plug, it will be the best 2.50 you have ever spent

 

[tantheman125]

2 miles of crusing and idling or 2 miles of balls to the wall?

balls to the wall