I have a friend of mine machining an insert....something simple. I couldn't wait for him so I had to fire it up last night and go for a rip....even with 3' high snow banks and black ice at every corner....... it sounded great and I can feel quite a difference. The holesaw cutting was a real pain at first so once I had a little trough cut into the pipe I drilled as many 1/8" holes as I could around it. It cut much quicker after that.
Again, great mod Snakeshack.....cheap and with instant results. Now I need to get a KLX needle and new main and then I'll be in business.
Oh ya! You think your happy now! I did mine and it's a different bike!
Also drill out your slide to 7/64th and remove your snorkel.
I got my stuff threw Schnitz (the home of the late great KLRCary) it comes with a nice "how too" sheet. I would start with the clip in the 2nd notch and a 142 jet (the KLX needle is much richer) with the mixture screw at 2 1/2 turns from the bottom. Mine feels great at all RPMs! http://www.schnitzracingstore.com/catalogs/catalog.asp?prodid=4929812&showprevnext=1http://www.schnitzracingstore.com/catalogs/catalog.asp?prodid=5007016&showprevnext=1