I'm running one on my 2018 KLX250. I am using with and without the quiet core depending on my mood. I love the sound without the quiet core but OMG is it ever loud! I can only handle an hour or two without the quiet core. With the quiet core the sound loudness is good but the quality of the sound is not as good.

 

 

I installed a barker pipe tonight. Very happy! The turn-down tip is very cool.

 

Long ago, after noticing the unusual midpipe design and then talking to Bill about his "findings" (with the Barker), I included a paragraph about the system on the "Exhaust Choices.." sticky.. WIth no member postings or forum data about the system at that time, I could only extrapolate that with a proper lidless CVK/EFI setup, the Barker may produce 25+ HP stockbores..

For any member that is running a Barker system + lidless airbox + proper lidless fueling, a good test for 25+ HP is a "max performance" 1-2 gear shift..

Holding WOT, "quick shift" to 2nd at 10k-10.5k ( holding WOT the whole time..) If done right, at power levels of 24(HP) or more, the bike will wheelie...

 

The tapered midpipe that expands as it enters the muffler is a very trick design. If I can get some actual dyno pull data, I will definitely share it. Right now, my plan is to extract everything from stockbore as I can. This means that your configuration and settings will be a good target for me.
I was thinking I might lose some low end grunt due to the lower velocity of exhaust gasses in the header as of this moment.. Last night I ended up only having the time to put the exhaust on. No rejet yet from DJ stage 2.. I will go lidless, reconfig the carb and MCM very soon.. That should make up for any losses between idle and 2000 rpms.

 

 

The black machined tip looks very nice as well.

 

The header has a "step up" in it.. It likely does not lose as much TRQ from 3k-5k rpm as the FMF's.. All being compared to the stock header....

Only Kris250 can offer dynobutt assessment of power levels in the lower 1/2 RPM range - compared to the stock header..

Surely you are not really concerned with power levels from idle(1300 rpm) - 2k... Does anyone actually ride below 2K or expect the 250 to perform in the "off idle" area ? It won't and never will !!

The lidless + full performance exhaust system is an exhilarating screamer 6.5k to 10.5k.... Adding MCM creates a broader power band that starts far lower in the RPM range. The bike takes on a whole new demeanor with great power everywhere.

 

You are correct. Idle is at about 1300. I suppose I meant under 4 or 5k. But thats not the case any way after some test runs.