Modern Vespa

Hey people!

I'm a complete newbie in internal combustion mopeds world (used to ride electrical Schwalbe ones before), so this probably is going to be a dumb question, but still.

Got a brand new Vespa Sprint 2023, 50cc (don't have time to upgrade to proper motorcycle license...yet ), and realized that on cold start giving it just a little bit of gas causes my Vespa to stall.

However, going full throttle makes it go with no problem. After riding around for 5 or so minutes and warming up the engine this problem (or peculiarity) goes away, and giving just a little bit of gas causes my Vespa to move with no problem. Did I got a Vespa with a defect engine, or it's just how low-power 50cc engines are? To give a little bit of context - it's around -1 Celsius (~34 Fahrenheit) outside, if that gives any additional info.

Hope I'm just a little dummy who didn't do his research, and not an issue with my engine!

How many miles / km has it done?

This isn't normal behaviour, and could be transmission related - clutch etc.

It's likely an easy fix, but you should have a full warranty - so I'd speak to the garage that sold you the Vespa.

It's brand new, so 0 kilometers. Strangely enough, it stopped doing it today. I will keep an eye out for it, and check in with my dealer - they can take a look and see what is up.

Thank you for confirming it's not a normal behavior!

It isn't abnormal for small engines to be more difficult to start in cold weather. The question is whether it's difficult enough to actually adjust, knowing that when the weather warms up it'll need to be adjusted again. When most people ride much more in warmer weather anyway, it might not be worth it.

Adjustments include increasing idle speed (easy) and changing carb jets to richen the mixture because of the denser colder air.

I just put up and shut up with my two-stroke 50cc, which isn't a Vespa.

EDIT: scratch all this. I live in the world of off-the-run scooters, and didn't realize Piaggio's 50cc engines were updated with fancy fuel injection technology.

It's fuel injected with an ECU. None of the above applies. Try starting it while giving it no throttle at all. Count to 10 while it warms up when it's freezing outside. Is it parked outside at night?

So, in the end it was most likely due to overfilled gas tank. Duh
ET/GT/LX: Hard Starting, Rough Idle, or Stalling