The next one I got from JFG Racing was a Non Air Striker and it looked like this.  Which type do you have, Air Striker or Non Air Striker?

When installed in the carburetor, you can see how the smaller cutaway tends to nest over the needle jet hood.  This nesting causes the vacuum at the hood to rise which pulls fuel from the main circuit at idle (a similar condition occurs when you install one of Lancer’s UFOs on a VM).  Is there a chance that you have a slide that is larger than a 7.0?  A larger cutaway could necessitate a larger pilot jet to compensate.  There’s always the possibility of a vacuum leak but you mentioned you have zero air leaks.

See how the #5.5 cutaway on the right tends to nest the needle jet hood while the #7.0 cutaway on the left pretty much leaves the hood exposed.

It’s easy to measure the cutaway.  Just place the slide on a smooth, flat surface and use drill bits to measure the edge of the cutaway.  Here you see a #7.0 slide being measured with a letter “W” drill bit.  A letter “W” bit is .386”, close enough for me.  Howzabout taking a measurement on your slide and let us know what you’ve got.

See how the removeable needle jet just unscrews from the metering block.  Note that it also has emulsion holes, that might be beneficial, or possibly detrimental.  Those holes and their placement can change the fuel curve.  Holes at the top affect part-throttle performance, holes at the bottom affect WOT performance.  Does your PWK have a removeable needle jet?

My needle jets are about .111”.  They are fixed and I’ve never tried to remove one.  Generally, needle jets are provided in sizes taken out to four decimal places.  I don’t have the tooling necessary to measure a needle jet to the degree of accuracy demanded, but I do have pin gages (only three decimal places).  My needle jets are about .111”.  You can try and check yours with the shanks of drill bits.  Be gentle, this component is critical.  A #35 is .110”. a #34 is .111”, and a #33 is .113”.  If you do check the needle jet, please let us know the results.
 
I do have the ability to accurately measure slide needles.  This table provides measurements taken off the actual needles.  The needles labeled with three letters (DGK, EGK, etc.) are genuine Keihin needles.  The other needles came from knock-off repair kits or knock-off carbs.  You may find the table useful.  As noted in this report, I had good results with a DGK combined with a .075” air bleed and a #140 to #145 main jet, but the needle was controlling WOT mixture.  I had superb results with an EGK combined with a .032” air bleed and a #135 main jet.

I use a wide band O2 sensor and A/F meter to confirm my jetting.  It’s far from perfect but it gets me very close.  I also should note that I favor rich mixtures, generally trying to hold WOT mixture in 11.0 to 12.5 range.

This report is about the main air bleed.  As you can see from my results, that air bleed has a significant influence on your main jet size.  As delivered, my PWKs had a .075” air bleed.  If your air bleed is larger than .075”, it will require a larger main jet.

Can you check your main air bleed and let us know what you find.  Just remove your mixture screw and use drill bits to check this hole (use the shank, not the cutting tip).   It’s easy to check.  You can use drill bits.  If it’s .075”,  a #49 drill bit will slip in but a 3/64” bit will not fit.  

Thanks Sneezy.  Hey, you don't need a lathe for this project.  You can trim that jet down with a drill and a file.