I don't have data to confirm jetting setups, therefore fueling curves, with snorkels in place. Pull the airbox lid and my setups apply. In your case, 140/2N. If the quiet tip changes throughput significantly, a smaller main would likely be more optimal - say a 136 or 138... The key is to properly fuel with lid off so you can get all the BIGGY power levels the Q4 will allow..

 

I'm not going to put he quiet tip into the Q4, just run it as it comes. Our trails are up to 94dba so I should be fine. It looks like anyone running the stock header with the Q4 (no additional quiet tip) and 140/2N-air lid removed is getting great performance

 

Yes, they are.

It takes time, effort, and desire, to learn about this stuff - it's doable, but to even be able to decipher my Dyno tuning threads, you have to have acquired "foundation" knowledge. When I joined, I expected to be able to find the "recipe" for proven power levels - but there was none, none in here or anywhere. So I aquired the knowledge, found a dyno shop, and after 22 or more dyno pulls, found the recipes.

I am not making opinionated recommendations. I'm simply sharing the information that I have found through testing the KLX on the Dyno..

 

I'm very grateful for all the work you've done to find the right setup for these bikes. The bike has great bones, just needed a bit more power. Also, the 13 tooth front sprocket I put on is a good low cost boost

I had mine out for the first time over the weekend, and I love the bike. It handles the trails very well and is very flickable. I even got a couple of feet of air over a small jump and it was effortless. The previous owner was about my size (225) and he has the suspension dialed in for aggressive "trail riding". I'm glad I went with this bike over the XR650 I was looking at.

 

Well, my Q4 and 140MJ came in the mail today. Anyone have any luck installing the MJ without draining and removing the tank? I was thinking of loosening and twisting the carb. Any thoughts

 

In the many dozens of times I've done carb setups on my bike, I've never tried it with the carb left on the bike.. When you remove the petcock mounting, just turn it to off..

But you only gotta do this once - do-up DJ140/2N, put on the Q4, pull the lid, clean the filter and leave either dry or very lightly oiled, and enjoy - you'll have all the power your bike can make in its' current "configuration" and you'll be DONE with carb setups..

 

Pulling carb on my 07 KLX250s is way easier than my KTM 640. Not "easy" but not half as difficult as it could be.

 

Well...I'm done and it's a totally different bike. Went for a short run last night and I can do power wheelies in first. Can't wait to hit the trails


Also, I never thought to remove the petcock. I drained the tank and removed the lines from the tank. Pain in the butt getting the lines back on. Your way sounds so much easier

 

Well, been away a bit and finally got the bike onto the trails. It pulls like a tractor in the low rpm range (almost impossible to stall, even on slow, technical, single track hill climbs), and pulls hard in the upper range. I do have bad bogging between 5,000 to 5,500 rpm. I have the air screw at 2.5 turns out. Any suggestions on where this should be. I'm having a very hard time getting any kind of screw driver in there and don't know how I'd ever not burn my hands if the bike were at operating tempature. Thx Kevin

 

The fuel screw is just fine where it is if you don't have decel popping. It will not effect any changes on the bogging.

Did this bogging start happening recently? When did it start happening? Please give more details about it while riding..

If it's been happening before and after the rejet, you have an existing condition that must be troubleshot and fixed.

At any rate, this likely is a slide issue - check the diaphragm for everything - creases, folds, pin holes, not sealed correctly etc.. Also, it is possible your '07 has a drilled slide..? If so, a 7/64 bit will slip through it - in which case, put the stock slide spring back in.

If you can't find anything wrong with the diaphragm and are sure it is sealing correctly ( when seated properly, the metal cap will drop down to metal-to-metal contact with the carb casting.) you basically have two choices - put it all back and see if the wrenching session made a difference, which is not uncommon, or put the stock spring back in for a test ride..

As you know, your bike is now making a lot more HP than before - about 22hp - any "weakness" in the old carb, iginition, etc will be amplified - I hope you don't have the butterfly shaft seal issue..
Probably outta look over this link https://www.kawasakiforums.com/forum...s-fixes-43146/