Low speed stumble

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KDXNOOB
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Low speed stumble

Post by KDXNOOB »

Hello everyone, first time post, got a new to me 04 KDX220, replaced the piston and kit with help from KDXRider, thanks everyone.

Now I need to troubleshoot a slow or low speed stumble.

Idle's good, but from just off idle to 1/4 throttle it has a stumble. By stumble I mean it doesn't run smooth and hesitates just a little. 1/4 to WOT it runs great. I have removed carb twice and cleaned, cleaned both jets with a small wire, tried adjusting pilot screw, no help.

It's completely stock, only mod I have done is remove the airbox tube, it has new plug, new piston and kit, it stumbled before piston and kit, it has stumbled sense I purchased from previous owner about 1 month ago.

Other question I had was is the stock air filter cleanable or throw away/replacement type. I looks stock, anyone recommend a K&N?

Any suggestions?
2004 KDX220
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rbates9
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Low speed stumble

Post by rbates9 »

For the stumble you need to go thru the jetting procedure in the "Jets and needles" section. What is your current jetting? You will probably need to go down a size or two on the pilot.

As for the air cleaner it is cleanable if it is in good shape. Or you could get a new pre oiled filter for $15-$20.

As far as the K&N, do a search on here. There was a topic not too long ago that went over this, and over, and over, and over it. :lol:
ROADSTR6
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Low speed stumble

Post by ROADSTR6 »

Sounds like a rich pilot jet. You may need to re-jet...especially if you are on the stock jets. For now, try turning out the air screw on the carb in 1/8 turn increments. You might find the happy spot that way.
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