Hey guys, I have been wet fouling plugs on my bike ever since I got it. It just about fouls out everytime i start it up for the first time after it has been ridden the day before. So I bought a J&D Jetting kit for it. I am still having these wet fouling issues however. J&D recommends using the #172 main jet for elevations from sea level to 3000 ft. which is me. I see that KTM runs a #168 stock. If i put in the #172, wouldn't that just make my problem worse? Either way, it still fouls with both of them in. Currently I am running the J&D jets with a #168 main jet, and with the red (leaner) needle and the clip in the 3rd position. Am I starting to get too lean with this setup? It still wet fouls though.

By the way I am running a BR8ES Spark plug and motorex cross power 2t at 50:1

I have the same problem sometimes, but I find I have a lot less problems if I shut my fuel off on the way back home and run the carb almost out of fuel before shutting off my bike. I think my biggest problem is I like a fat jetted bike on the bottom for better bottom end power and that makes my bike very rich on the pilot jet and you have better chance of fouling a plug at start up, but once I am warmed up I never foul. I have thought of mounting a small screwdriver holder on my bars somewhere and use it to open up my air screw 1/2 to 1 turn out when startin and when warmed up close it back to the position that has the best throttle response just off of idle.

The problem you probably have is your pilot jet is not the right size or your air screw is turned in too far.

Doesn't sound like a bad idea to try shutting off the fuel and running it out before stopping, I'll try that next time. But I think I probably still have to screw around with the jetting somehow. There have been times that I have had my bike off for like a 15-20 min break after riding and I will go to start it up and it will run for about 10 seconds then die and foul out.

float level? Reeds? topend? repacked silencer?

JD uses a needle that requires a larger main jet. If you are still fouling plugs, something else is going on.

You don't mention what pilot you are using, or what the airscrew setting is.

My 04 250sx tends to load up a little when cold. I turn the choke off as soon as it starts, and then after 10-20 secs of idling and blipping the throttle, I'll start off riding slowly, and gradually build the revs over the first minute til it clears out. If you rev it too high right away, I think it's possible for it to suck a big handful of that excess oil in all at once and foul the plug.

I don't think you're too lean.

Thanks for the responses. The pilot that Im using is the stock one, whichever that is as J&D doesnt provide a pilot. The air screw is out 1.5 turns as is recommended in the manual. The tailpipe was just freshly repacked and only ridden on a handfull of times. I have never touched the float level. The reeds are Vforce. and I dont believe that the engine has ever been rebuilt.

jhm1138 said:

have you checked the condition of the reeds?

I have a JD jetting kit for my 08 300XC and for sea level up to 3k I am running a 162 and that is by the paperwork that came with the kit I have also been running the needle by his sheet depending on temp. I know sometimes the 250 and 300 kits are the same. You could email JD I had a friend do that and he was very helpful. I am also running a 38 pilot jet in an attempt limit boiling over and it gave it a little more bottom torque. Chazman out of Colorado is also pretty good with jetting issues. I am not sure if spelled his call sign right.

Stock pilots are usually 3-4 sizes too large. They do a great job of fouling plugs (too large of pilot jets).