OK...he didn't clarify. It sounded like he had a DJ 120. I'm still questioning that needle clip position. The main has some influence on needle position to be sure, but in the top groove?

 

According to that chart... if he is at a DJ 120... that's about where I'm at with the 127.5 from the dealer with a header and minor box mod (snorkle pulled) and mine was also so rich it bogged and sputtered through the mid range with a 130 and 132 (relative 124.)

 

120 is too small. i run a 128 and its still a tad lean.

 

Jackson, you mention a 127.5 main. In Keihin jets I haven't seen that number for the CVK34, and doesn't Kawasaki use Keihin jets? Not saying you don't have a 127.5, but just curious about that number.

 

Yes, i was curious too as I hadn't ever seen that number tossed around on the threads and I specifically asked him if he had a 128, and he said no.... The guy I go to parts for used to have a KLX 250 in 06 and he modded his out with KLX 300 parts so I thought maybe he did something from that end? Either way, I ordered the jets from 127.5-132 and it was the 127.5 that really opened it up, and they fit so if it aint broke...?

 

To answer some of your questions:
PSUdude85, my pilot jet is stock, I do have an adjustable idle needle jet set at about 2.5-2.75 if I remember correctly. My airbox mods are; the part of the snorkle inside the airbox has been removed, the snorkle on the outside of the airbox - the bottom of it has been cut from front to back leaving the bar in the center to keep it from collapsing on itself. The screen had been removed from inside the airbox. And I'm ordering a K&N airfilter today.
Jacksonriding7, the header is stock, but planning to go meagbomb when I can afford it.
Fooswolf, excellent information! That does explain why my jet seems small.
Westozklx, not lean. I started with a DJ128 main 3rd notch down like recommended in instructions, it ran so rich I could see black smoke come out the exhaust. Moved the C-clip one notch at a time until it reached the top then dropped down to a 124 main jet. Started at the 6th grove and worked my way up to the top groove, just about cleared it out but it was still rich by how the bike responded. So I ended up w/ the DJ120 which is the smallest jet in the kit. I did the same needle positioning as I did on the 124 and it did not clear out until I was on that top notch.
TNC, when I wrote my original post I put down DJ kit I was assuming you guys would know I would be using their jets, sorry for not clarifying that. I do respect your input on these issues. I find the needle position shocking too, the only thing that I can think of is the part of the carborator that the main jet screws into and your needle rides in has a fairly big inside diameter, compared to the DJ needles outside diameter. Comparing the DJ needle to the factory, the DJ looks smaller in diameter and has an aggressive taper at the end. The factory needle appears to be bigger in diameter and has a gradual taper.
Is it possible that the 300KLX carborator has a smaller diameter hole where the needle sits compared to the KLX250S?
By looking at the plug, it appears I'm still a little rich. By dropping down 1 more jet size I would think I would have to bring the needle up to compensate for the smaller jet in my midrange.

 

Your choke (enrichener) isn't on is it?

 

That's a good idea to check. Though unlikely, the choke being held open a bit or the rubber sealing portion of the choke being damaged and not sealing properly could cause a rich condition. His situation seems rather uniform, however.

 

Choke works fine, idle is at the same rpm as it was before I did the changes. I would think if it was choke issues I would get a high idle.

 

loco, on your question about the 300 carb being different in its jet and needle interfaces compared to the 250, I'd say no. Many use the 300 DJ kit on their 250's...I do...with no issues and fairly consistent results. I don't think I've ever heard of one quite as different as yours. Your mods are common and nothing seems amiss, so it's odd indeed. The fact that your bike seems to run fine and even to redline would seem to indicate correct jetting for the most part. Your numbers are just fairly different from most. I'd like to hear what mileage you get.