Screens for Bikes has a klx400 screen that I think will work. Do you know or have pics of one installed?
Screens For Bikes

 

i have searched high and low when i was searching one for mine and i found this :

https://tciproductsusa.com/index.php...af423268e421b3

im quite satisfied with it, can feel the improvement

 

Here is my KLX650 with the National Cycle Deflector Screen with the quick release mounts:



I can take it off at the shield for cleaning, or at the bars when I don't want it on the bike. I use the zip ties to keep the hose from any chance of catching over the *****. About 20,000 miles and it works great. I used split PVC water pipe tubing, 1/2" I think, and some coil plastic brake line wrap to shim the 7/8" mount to the smaller crossbar. I also slightly trimmed the angle in the center using tape and a hacksaw blade to make it conform closer to my headlight nacelle.

There are multiple ways to fit the bracketry, this set up worked well for me at the time.

The best part is the quick release for cleaning and for removal/re-installation.

 

https://tciproductsusa.com/index.php...6b2d71a71e3fa5


KLX250SF / S - Kawasaki - Shop by Bike - TwistedThrottle.com

 

Here's the windshield I used for a SS1000 and BB1500 ride. It was a $15 Craigslist special. I don't know what brand it is or what it was originally intended to fit, but it does work surprisingly well.

Front:




Side:




Ron