I have posted here before, I bought a really rough 2009 and over the winter fixed the cosmetics and did the low buck mods to the drivetrain.
I moved the camshafts and removed the automatic compression release, I bought the Klx300 jets and installed them, i opened up the hole in the slide, I set the valves, removed the air box lid and installed a DG muffler.
I did not ride it much stock but of course the difference is amazing, it has plenty of power, you find yourself over the speed limit constantly, going 75 mph down the highway, it still has a lot more throttle to go and you can tell it would go quite a bit faster.

Very fun ride, albeit a little noisey, might have to make a quiet core for the muffler.
I love riding the bike, I have 6 others and this one is very fun.
The jetting seems to be good, #40 pilot, 128 main, mixture screw 2 1/2 turns out, N1TC needle #2 clip position, and I plan to try and balance gas mileage and power, as I continue to mess wth the jetting.
My only complaint is; the transition from no throttle to open throttle is sluggish, it's like it needs an accelerator pump.
But I don't consider myself done yet.

 

Brydjo, what is your elevation ?
When you say "no throttle to open throttle is sluggish" , exactly what RPM are you snapping WOT from ? How is the snap to WOT from other starting RPM's ?

 

We are 600-800 feet, RPMs maybe 3000-5500 anywhere in this range, I suppose you get enough RPMs going and off throttle to on is quick enough, it's like when you are at low speed in first and you yank the throttle open, it doesn't stumble, it just takes off gently and very soon picks up enthusiasm and starts to really accelerate.
I thought I might richen the needle at some point, and see if it goes from off to on with a little more drama.
Again it sounds like a person could get quite a bit of an increase, but the fuel mileage could get down to the levels of my Kaw Triples!

 

Around town driving fuel mileage is personal to you.. Fuel it for max power (your doing max power tuning if your going to use the KLX300 carb components), hoon it on the street and you'll get the mileage you deserve..

Your setup will produce better curves than my bike/DGR charts.. The #40 pilot will let the MCM roar compared to my stock #35.. The N1TC needle will fuel the midrange better than my DJ needle.. I have no idea how the drilled slide plays into this - I did all you've done on my KLX300 (with a DJ kit) and the results are incredible..

TRQ (with proper carb setup) comes on strong by 4k rpm and holds well to redline..
Your issue is with the transition from pilot system(pilot jet size/fuel screw setting/float level) to the primary circuit ( needle/needle setting ) ... I am sorry I don't have data using those components but there is 22+ HP and 16.5+ Lb Ft of TRQ in your bike to unlock with your carb setup..

Carb setup done right and there is power wheelies in first gear with a snap to WOT from 3.5K RPM - NOT a dead spot lacking power..

I could only offer opinions on what you should be doing. Stuff you probably already know.. Does it start instantly warm and within a revolution or two cold? If not, there's a problem, because it should.

My bike and elevation is identical to yours and, with the DGR, everything is too lean with a DJ kit using a DJ 136, DJ needle on 5th notch down and #35 pilot with screw 4 turns out.

 

Thank you for the reply, I'm going to have to read this over a couple times and think about it!

 

My bike is now starting very well not even a half a turn when it's warm, it's the snap open the throttle power wheelies that I don't have yet that I'm looking to get.

 

Agreed.. Check out my "After Mods Wheelie Video" below on my signature line.. The video was made before I was using 136/5N so it makes quite a bit more TRQ and HP now.. This is HD video so set your viewer to at least 720P and you can see the RPM and MPH I snapped to WOT at...

Again, your bike should easily make more power than what your seeing in the video.. Also it was 100 F out there that day..

Full disclosure: I'm 6'1 220lbs - weight mostly in upper body.. When I ride it now, it wheelies effortlessly unless I'm sitting on the tank..

 

I am wondering about the slide return spring because I know that on the jet kits they use a lighter spring than stock. Just a thought.

 

Yes the 250 kit uses a lighter spring and does not call for drilling the slide..
Ok, did a little research in here.. Looks like your #128 keihin main jet is perfect for lid off..
So..Just an opinion - reset needle clip to middle notch (3rd) , and try your WOT snap.. If no go, start turning IN the fuel screw 1/2 turn at a time from current 2.5 turns out.. (That #40 is a biggy pilot jet and , maybe IMO, COULD over richen the idle circuit even more than the MCM wants - again, just my opinion)

 

Again, thanks for your opinion, moving the clip will be the next step, if I can keep off the bike long enough to work on it, it is finally warming up and I am getting some miles in the Green bike, I'm really liking it, just riding around is quite fun, I am looking forward to things drying out enough to get off road.

You can really see why some guys take long trips on these, it is not out of the question, smooth enough, comfortable riding position, enough power, seat might need some bubble wrap for 200+ mile days, yes bubble wrap, the bigger the bubbles the better, take a 1 foot square put it on the seat, really adds to the miles a person can tolerate. (Free touring tip)