Polini PWK carb

[Ballspeed65]

Has anyone used one of these? Any good?

[coaster]

I have tried the OKO and LTH PWK copies and they work ok but the PWK design has a very small float bowl so fuel level is critical. If you installation requires the carb to sit at an angle then that makes it worse. I took mine off my TS1 after a mild sieze, the carb might not have been the issue but it was always at the back of my mind if I held it at above 50 or so for prolonged periods.

[Fast n Furious]

As Coaster says:- They can be a problem when used at an angle especially if you are expecting to use the power jet.
One way around this is to use a vacuum fuel pump to provide sufficient fuel delivery.

[Warkton Tornado No.1]

I've not used the Polini PWK, but there are other manufacturers that make PWK carbs under license besides them.

I strongly suggest you invest some time researching the internet for information of how they should be 'blueprinted' which includes setting the float, ensuring passageways are adequate etc. I'd be very surprised if the Polini needs any modifications.....

That said, it is very worthwhile modifying the floatbowl so that the pilot jet is removable without having to remove the bowl itself. You can see how this can be achieved via:

http://www.mid-atlantictrials.com/Instal.html

I think the PWK carbs are extremely good as they are easy to set up, are relatively inexpensive, work very well with an adequate air filter & do not have any tendency to flood (built in float bowl overflow), unlike one round slide type that is extremely popular with many lambretta users.

[Storkfoot]

I wish I had seen that pilot jet modification when I used to use these carbs years ago. The reason being that if you are setting up the carb, you forever have the float bowl off and the floats are very easy to knock when you do this. So, when you put the float bowl back on, the float height has altered sometimes causing you fuel starvation.