Jump to content

Replacement jet block oring for Keihin short body PWK38

Recommended Posts

These things have been unobtainable until just recently.  The standard PWK jet block oring does not work with the short body carb, which uses a slightly different pattern.  The standard PWK oring can be modified if you're real slick or you can contact the guys at STIC and have them send you the correct part.  It is a little thicker than the stock oring as it is intended to work with their jet block but it looks like it should work with the stock PWK jet block as well.

You could always buy the upgraded jet block at the same time too.  I have not tried it but I regained a good amount of lost power just by replacing the oring, and the carb fuels very crisply at low throttle applications.   It has never run this good.  I suspect there are a lot of bikes running the PWK38S out there that could be running better.  This carb was used on the KX250, YZ250 and RM250 and probably others since the late 90's.  Pretty much all of them could use a new one unless your original 10-15+ year old oring is still somehow getting the job done.

20170721_172934.jpg.040159243451a8ca5974aca7c874679a.jpg

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for  the tip. This carb is somehow common and yet hard to find parts for, besides the shared ones with other pwk. I've been needing to replace my jet block oring 

Share this post


Link to post
Share on other sites
On 7/21/2017 at 7:18 PM, turbo dan said:

These things have been unobtainable until just recently.  The standard PWK jet block oring does not work with the short body carb, which uses a slightly different pattern.  The standard PWK oring can be modified if you're real slick or you can contact the guys at STIC and have them send you the correct part.  It is a little thicker than the stock oring as it is intended to work with their jet block but it looks like it should work with the stock PWK jet block as well.

You could always buy the upgraded jet block at the same time too.  I have not tried it but I regained a good amount of lost power just by replacing the oring, and the carb fuels very crisply at low throttle applications.   It has never run this good.  I suspect there are a lot of bikes running the PWK38S out there that could be running better.  This carb was used on the KX250, YZ250 and RM250 and probably others since the late 90's.  Pretty much all of them could use a new one unless your original 10-15+ year old oring is still somehow getting the job done.

20170721_172934.jpg.040159243451a8ca5974aca7c874679a.jpg

Dan when you say you have not tried it are you referring to the jet block or the stic o-ring? Last I read you hadn't installed the stick o-ring and had no plans of doing so unless your carb started acting up. 

Share this post


Link to post
Share on other sites

Have not tried the jet block yet.  Just by replacing the o-ring and getting the carb working properly again I gained a noticeable amount of power. 

The stic oring would have been nice to have when I had the carb apart but the modified o-ring I ended up using is still working great. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×