spark plug problem with my kdx 125

[wumember]

hey guys, how are all of you, ok my prb is that i buy a new spark plug and everything is perfect, after some time my bike starts choking when i feel the kips open(i mean when the bike is at very hi revs) this doesnt let me get any speed, if i leave it alone the bike will get to a point werer i cant even ride... it chokes when warming it up and everything.. if i change the spark plug the bike is perfect and runs well, i'm putting in the NGK B8eS, all the people at the bike shops tell me its the original, what do you guys think aboput this problem... thx

 

[Dogman5]

Originally posted by wumember
hey guys, how are all of you, ok my prb is that i buy a new spark plug and everything is perfect, after some time my bike starts choking when i feel the kips open(i mean when the bike is at very hi revs) this doesnt let me get any speed, if i leave it alone the bike will get to a point werer i cant even ride... it chokes when warming it up and everything.. if i change the spark plug the bike is perfect and runs well, i'm putting in the NGK B8eS, all the people at the bike shops tell me its the original, what do you guys think aboput this problem... thx

Some possible problems could be jetting. Is it all stock jetting? Stock jetting is always usually a little rich, which can cause problems as fouling plugs and/or spooge out of the muffler. If the stock jetting was too lean, there would be a greater risk of seizing the engine.

But try a jet kit, but the first and most sensible thing I would try, would be running diferent spark plugs. The original standard spark plug is not always the best option, and I'm not even sure if the ES is the original spark plug, is it? I can't remember on mine. So experiment with different spark plugs, (maybe a BR8EG?) and then if the problem keeps occuring, buy a jet kit and rejet it. Carb work can be scary, but its no big deal when you get a good understanding about it, or know someone who has done carb work in the past (many old car enthusists and dirtbike dudes can help you there) And check out www.ericgorr.com for his carb tuning articles, and check canadian daves carb tuning post for kdx's as well!

 

[kawa06]

I just bought my '03 kdx in september, and I had the same problem. New spark plug=great ride (with considerable spooge). I was fouling plugs (br8es-stock) about every 40 miles. Here's how I fixed it:
1. Toss the airbox lid...or do like I did and drill holes in the lid - The bike will be a lot louder, but it's well worth it
2. Change that spark plug-I went with the BR8EIX just because it was one of the plugs recommended by NGK...a lot of other guys recommend the BR8EG which I am sure works just as well (both are finer wire plugs)
3. With these changes it's time to rejet. Go to the just kdx page http://justkdx.dirtrider.net and read the carb sections of the tech tips. If you haven't jetted a carb before, you will probably be like me and have a lot of fun with this part of the process. Good luck with this...once you get the hang of it, it isn't that bad. Frustrating at first...yes, but the difference when you finally get your bike properly jetted is amazing. If you have jetted before, good for you-you'll have no worries

Good luck...hope this helps