Troubleshooting Vespa si carb fuel starvation issues & drilling the float passage

I was having fuel starvation issues at WOT on the Sprint Veloce, so I went through the various potential causes, eventually drilling the carb float passage to fix it.

[@supunudaraka4485]

❤

[@miljtube]

Is this modification only for tuned engines or is it useful for factory engine? I have a vespa px 200. Thanks.

[@ChandlerHowell-Vespa]

It's really only necessary on tuned motors. The float passage only becomes a blocker when you're dealing with larger main jets.
If you're having fuel starvation issues like this on a stock motor, it most likely means you have a blockage or bend in your fuel line.

[@ryanseddon4800]

As an addition I have had talks with 125 px owners saying that the fuel passage is too narrow as stock and drilling out the px SI carb. was helpful. I dont know if this is true for all SI carbs. but there is a feeling that the manufacturing process for some si carbs doesnt creat a wide enough passage for the fuel.

[@ChandlerHowell-Vespa]

@@ryanseddon4800 Unmodified, the float passage is only capable of keeping up to about a 125 main jet. I've never seen a carb that couldn't keep up with stock jets, but it's definitely something to modify on tuned bikes.
SIP sell an SI carb with the entire fuel path opened up, but that's what I was running and had to modify when I made this video, so take that for whatever it's worth.

[@selefr8317]

2 mm es correcto?

[@ChandlerHowell-Vespa]

Correcto