Modern Vespa

So my jetting seemed spot on until I open it up for 90 seconds and then it overheats(read seized). After reworking the head to lower the CR(it was awful high for pump gas ) I've taken a look at the (not adjustable) float height. What a load of crap. The float valve is fully closed with the float almost to the bottom of the bowl. If I push the float down to depress the spring mechanism built into the needle I get about three times more travel. What ever happened to quality control? meh.

AAAND there it is

Yeah that's a downer without a metal tab that allows for adjustment!

Same carb, looks like they revised it a bit. I've already installed one on a friend's smallie with a Polini 130cc kit and it's fine...

some carefully applied heat may allow adjustment of the float height. I'm running a Polini pwk 24, which does have the metal tab for adjustment; however my float height was spot on out the box. Float looks similar, I wonder if it can be replaced with the pwk version...

Thanks for those pics! That's how mine looks if I swap in the shorter needle from a PWK.
I kinda look for the seam of the float to be parallel to the mating surface when no spec is given. I'm running a topped, tailed and exhaust ported Polini 130 w/reed intake and PM40 pipe, so I'm not so comfortable anymore with that shallow float bowl and questionable float height. I might have to move ahead with my customized intake arrangement for the PWK28. The CP was so easy to set up though.

Might be on the right track. Got the needle seat out and found the side facing the rubber tip of the needle is flat with a hole while the side facing the fuel line is conical, like the rubber tip of the float needle fits in it like a glove. If I install the seat with the conical side facing the needle I get about a mm deeper before closing.

that's awesome!

how do like those carbs?

I'm torn between mikuni TM24, a PWK or the polini. I want to outfit the smallie, the S1 and the SX150 with the same carbs so that I don't have to triple up tuning spares.

thoughts?

Your orange smallie has the cp21, they are pretty easy to dial in. I like 'em.

hmm... the decision may have already been made for me...

OK, total failure. Screwed the pooch. Crapped the bed. Don't do what I did.
Ordering another because that's the shortest route to success and clocks a ticking for RoM. And Treats has 15% off Valentines sale, promo code "glizzymcguire" until the 20th


Greasy. the CP is the easiest carb Ive ever set up, float height issue aside. That said I aspire to fit the genuine Keihin PWK(Polini is making a PWK now too) on modified Strohspeed reed inlet(though if I didn't already have said intake and carb I'd be going with the new Falk one).

I've got this Polini PWk 24 on my smallie, with Polini 130 cyl & all the fixings. It fits well, easy to tune, and top notch quality & machining; IMHO. Easiest to tune carb I've had in a while. I plan to use the same type of carb for other builds, as I invested heavy in a wide range of jets and needles.

https://www.treatland.tv/polini-PWK-24mm-carburetor-p/polini-pwk-201.0166.htm

Went ahead and took advantage of Treat's Valentines discount. New carb float level is much better to my eye.

nicely played. I may pick one up to play with as well...

now, stop being a tease jean shorts and show us the manifold!!

That's a different thing. For a PWK28. Right now I'm sticking with something more proven. When I get the other worked out I'll share.

look forward to it! you always bring the heat!

what's your current set up and what spurred the change up?

Well I sold the orange small state so now Im playing with the same thing, but polini reed inducted, topped n tailed Polini 130,reworked the head, bullnosed crank, pm40 pipe, fly tech 1.4kg ignition, short 4th, 27/69 gears, cm4 clutch. I think it would use the 28keihin I have and I had an unused Strohspeed intake for the Polini reed block, but it'd for like 35mm carbs. and it's a super tight fit. I'm trying to bypass the rubber mounting and plug it right into the ID of the strohspeed intake.That makes more room. I'll show you when I have it finished. For now the cp24 should do the trick.