KX Guru Racing

It may be worth your while to run a 38 air stryker on one of your 500's just to see the difference in throttle response.
It works great up here in the mountains. I rarely got in to 4th gear unless we were running from trail to trail on fire roads. You will lose some top end, however having enough real estate to run wfo in 4th or 5th on a track may be worth the trade off on intake velocity on the bottom end. Just a thought, I'm no expert by any stretch!
Tuck\o/

Your stealing my thunder Tuck!
The carb in the pic is a 38mm...
Although we are still not decided if we are going to use it or not yet.
We actually have four different carbs we are considering.

Now, here is a little bit of info that will be coming out in greater detail later on in the build

This is direct from Adam Millar from Millar Racing Engines regarding the 97 KX250 carb... Which is the same as the 2000 CR250 carb..
This info is in a hidden section of our forum so don't go blind looking for it

Adam uses a new 2000 CR250 carb which is the same as the 97 KX250 carb for his pulse induction.
If you take anything away from all these notes, it should be this If you have one, (2000 CR250 Carb) run it..
The 97 KX250 carb Keihin 38mm air striker or 2000 CR250 Carb flows higher velocity under half opening then any other carburetor tested.
At full throttle it flows more CFM and more velocity then a 41mm PWK.
The 2000 CR250 or 97 KX250 Carburetor is better and makes more HP and Torque with no funny business then the PWK, Smart carb 38mm or 40mm, or the PWM.
And that is without the new metering system that is really suppose to be great but will be fully tested once Adam get's his hands on one.
The new metering block runs about 350 US.
It is a billet metering block that you bolt into your air striker pwk.
It has a finer adjustment to it as well as another air bleeder on it.
It makes a lot of fuel lift at low RPM which makes it easier to get a crisp throttle response off the bottom.

You are all over it again my good man! Thanks for the " secret thread" teaser I also want to thank you for taking all the time and extra work you do to keep recording your findings and sharing info.
I certainly understand why most sites never publish their R&D findings to try and keep any advantage possible over a competitor.
Keep up the great work!
Tuck\o/

Thanks Tuck...
I'm just a blabber mouth...
I just want to help keep the K5's alive and going... plus I like to stir the pot occasionally

Nothing worse then working with hardened vent hoses...
So I ordered some new stuff..
And, a carb rebuild would not be complete without a bath in the ultrasonic cleaner..
And I hate to admit it but I didn't like how the first swingarm was turning out
Lessons learned... Time for Rev 2

What???

Ok... I've been stuck working on my old house that I am selling and have not had a bunch of time for this project
But, the good news is I should be done tomorrow with a little more clean up

Soooo... This will give you a better idea of where I am headed with the rear caliper.

This is a rough cut of what it will finish like...

A little more clean up...

I have been so busy with getting my old house sold and dealing with day to day shop issues that I have not had any time to do more work on this project.
Now that all that other trivial stuff is out of the way I can focus a bit more on this project

This is not Chichanium
Half the weight of the steel studs and will not rust or corrode...
I like it