09 has a different needle to the 300 and 06/07 kit. The 09 kit also gives you a new spring instead of asking you to drill out the slide hole.

I believe the 300 kit still brings the best performance on all models.

Paul
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Lovely Wendie99

 

I've been trying to figure this out as well.... as i also have a 2007 KLX250 which is not specifically listed on the the Dynojet website.

On the DJ website it appears that there are three kits listed for the KLX250/300 ... 2152, 2182, and the 2206.

Both the 2152 and 2182 kits have the same parts listed and include the spring, but do not include the drillbit for the slide, nor is drilling the slide mentioned in their pdf installation instructions... i did note that they both provide the same part number on the needle.

The 2206 kit for the klx300 does not include the spring although it does include slide drilling instructions/drillbit, although the part number on the needle is different.

So i guess my follow up question would be...
1, what's the difference in the needles between the 2006-klx300 and the 2009-10 klx250s/sf...??
2. why doesnt the "new" kits instruct to drill the slide
3. does it really need a new spring..?

I was thinking that they may have designed a better needle for the 2009/2010 models and that they figure everyone already knows how to drill the slide and dont want to bother supplying the drillbit or complicating the instructions..?? just wondering why they didn't include my 2007 model for this kit.

I guess i was thinking of going with the 2152 kit since it included the spring and provided a few more jets although i am concerned that i might be missing out on the performance of the klx300 needle.

anyone got any thoughts on that one..??

 

300 kit is the one. The needle taper is 'more agressive' and suits the 250 just fine. The new 09 kit has a 'softer' needle and comes with a softer spring for the carb', otherwise they are the same.

 

:d:d:d

 

NorthRider the idea behind the softer spring or drilling the slide is to improve the throttle response by allowing the slide to lift faster. You can do this by either using a softer spring or increasing the diameter of the vacuum port in the slide. You do one or the other, thats why if the kit includeds a softer spring there are no directions for drilling and no drill bit.

 

I guess I have a language barrier problem. We do talk funny up here, you know.

What do you mean by "softer?

In the picture the 300 needle looks to have a double taper and appears substantially richer.

Ron

 

I believe it's not as aggressive as the 09 needle.

Go the 300 kit

Paul
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Buick Ln3 3.8L Mpfi- How It Works

 

I still don't get it.

Needles are passive. They vary the mid range mixture (richer/leaner) by their shape. What's the connotation of aggressive or non-aggressive?

Ron

 

The needle in the 2009 kit has a very smooth taper (non-aggressive), the older needle has no taper initially then almost a step where the taper starts (aggressive); the taper is a bit more pronounced as it is shorter.