Float needle valve looked brand new as it should.  It's not the problem...

Best photo I could get trying to manage the carb in one hand and phone camera in the other.  The float height is set to about 16mm.  It looked better in person without a phone in my hand and I was fiddling around with it.

The clip position after adjustment.  The photo before adjustment is crappy.  

Real technical - I bent it down a little bit.

Latest update.  

I installed a UNI 4” pod foam filter directly to the carb (no snorkel tube or air box chop job).

Pilot/idle circuit = still great with the #32 jet.  Only needed to turn the a/f mix screw about 1/4 turn richer.  It’s about 1-3/4 turns out now.

Midrange feels pretty good, maybe a tad rich with the e-clip in the middle groove still.

WOT - While the midrange can find a fairly happy place with a 120, 122, and 125 - I’m struggling a bit to get a nice clean WOT response with the UNI filter installed.  The #120 seemed lean.  The #125 seemed a little rich.  Bought a #122 and I’m perplexed with it.  I can’t tell if it’s too small (lean) or too big (rich).  It can act “clean” sometimes.  If I sneeke up on WOT, it’s generally okay.  If I roll on the throttle hard when I think I’m at a good rpm level, it just isn’t clean.  It actually backfired out the stock exhaust rather loudly (haven’t heard a bang like that before through the stock exhaust).  I’m coming to the conclusion that I need to install the Harley dyna muffler to open things up and get WOT to feel right.  Thinking the stock muffler is just too restrictive with the PWK38 and UNI filter.

Thoughts?  I wish I could describe the performance feel better.  It’s just not always “clean” - like it’s lean sometimes and rich other times.  I got the boomer backfire when I was hammering it pretty hard in 2nd.  I can creep up to WOT in 4th pretty cleanly.  Hit 84mph in 4th getting on it last week.

The UNI filter does sound cool when you can hear the air induction!

Update:

With the UNI filter and stock muffler, here’s where I landed on jetting.  I’m happy with the results for now.  

Easy start, clean idle, acceleration is brisk, no backfire on deceleration (an occasional light crackle if I close the throttle quickly from 5000+ rpms), no kabooms, WOT is clean, no heavy exhaust fumes smell.

The final adjustment was moving the e-clip up 1 groove on the needle from the middle position to the 2nd leanest position.  I need to monitor this because I don’t want the bike running too lean, but I think this is the right position for my setup.  I was and I’m still a little concerned about this e-clip position.

Pilot Jet: #32, mix screw 1.75 turns out
Main Jet: #128
Needle: I think it’s a “DDJ”.  I’m pretty confident in the J length.  The needle is not marked on this knock-off $36 carb.
E-Clip: 2nd groove from the top of the needle

I need some riding time to calculate MPG.  Hoping for 55+mpg riding it like I didn’t just steal the bike.

If I decide to stay with this setup and not install the dyna muffler I have handy, I may experiment with a slightly longer needle with perhaps more taper.  It seems to want to go a tad rich around 3/4 to 7/8ths throttle. OR go back down to the 125 main jet while keeping the e-clip in the 2nd groove.  I’m really close, but not perfect.  I kinda want perfect.

DragBikeMike wrote on 07/01/24 at 23:19:33:


Thanks Mike.  I need to give this setup 200-300 miles and see what I think.  Yup, love the price!

Aside from improved performance and throttle response, a couple things that I really like about this setup.

1) the UNI Filter butts right up against the airbox (which is now just a giant breather tube puke catch bucket).

2) I can swap the main jet in less than 5 minutes once the seat and gas tank are removed.  Obviously disconnect the fuel line, pull the carb top, slide, and throttle cable off, loosen the band clamp at the intake manifold, and gently rotate the carb 90° to get easy access to the plug at the bottom of the float bowl to access the main jet.  Unscrew the plug and swap the main jet (being careful not to lose the washer on the jet).  Reverse steps to reassemble.  I’ve got the whole process down to about 35-40 minutes with a smoke break.  Changing the e-clip position on the needle is a bit more convoluted with the way the throttle cable ferrule is trapped by this funky contraption in the slide.

I know it’s conceivably possible to change the main jet on the stock carb without removing the carb, but it’s a pain and unnerving.  I’ve always had to remove the carb to change jets which means several extra steps - like pulling the battery and battery box to get some room, and removing the snorkel (air boot) between the carb and airbox.