JD Jetting carb ordered - but sending back

[JFRM250]

I recently ordered a JD Jetting JDKHO8:  https://jdjetting.com/product/jdkh08-keihin-38mm-pwk-airstryker-w-jet-kit/

My existing carb is giving me fits (let's not get into the why's and all that).  Trust me, I've done just about all I can with the existing stock carb following a complete top/bottom end rebuild.

Anyway, the JDKH08 is what JD Jetting said would work for my 2001 RM250 (as did Motosport, which agreed that this would be a replacement that would work/fit fine).

It does not.

First, the top of the JDKH08 is 'round' whereas mine is more than oval/football shape with 2 allen screws in the top.

Second, the top to bottom dimension is the same at about 6" but the front to back (intake to boot) is a full half inch shorter (at 3 inches) on my existing PWK38PWJ/TPS than it is on the Airstriker JDKH08.

JD Jetting (and as it goes, Motosport) offers an 'AG' model which perhaps is what I'm looking for?  I've sent this inquiry to JD Jetting as well.

Maybe you guys think that, despite the front/back measurement making thing notable TIGHTER in there, and despite the top round vs oval factor, I could still make a JDKH08 work somehow?  If so, how?  The Airstriker is supposed to be a VERY decent replacement for the stock carb.

 

[DEMI]

the screw top is longer, not sure why they would say that is ok versus the AG version that came stock. I'd want one that fits. 

[JFRM250]

Here’s the quick and largely unhelpful response I received from JD jetting when I explained everything to them in an email. I think I might have to pick up the phone for this one:

“that carb fits you just have to squeeze it in . there is no difference in performance.”

(Nice, huh?)

[DEMI]

probably isn't a difference in performance, screw top is a good carb, that is besides the point however. Fitment issues are no fun and they have AG carbs. Send it back. You can probably wedge an Edelbrock in there too, doesn't make it right. 

[jaguar57]

Your stock carb is OK, you just need to jet it right. I have decades of experience but still I was stumped recently with my Suzuki AX100 street bike (two stroke). I fiddled with it a lot but had no idea what needle to try. That is because you can't know without a jetting calculator. So then I made my own calculator (http://www.dragonfly75.com/moto/selectNed.html) and figured out what needle would smooth it out. I want to make a video demonstrating an example case of a bike more common than the AX100 so if you are interested and can follow precise instructions then we can make this a project together. (photos also are needed)

[JFRM250]

Thank you for the offer and I will give this approach an effort as time permits. Will be in touch in this thread. Thanks again!

[JFRM250]

On 7/17/2019 at 4:24 PM, DEMI said:

probably isn't a difference in performance, screw top is a good carb, that is besides the point however. Fitment issues are no fun and they have AG carbs. Send it back. You can probably wedge an Edelbrock in there too, doesn't make it right. 

Or a Holley 4 barrel, lol.  Point taken.