Modern Vespa

I once fell on my side with my Primavera and noticed that it automatically died when it was sideways. I tried to find that is it a feature and didn't find anything about it. Now it came to my mind randomly and didn't find anything again and now I'm asking from you guys this. Is it a feature and how does it work? If it's not, how did it die when it was sideways?

Piaggio scooters have a rollover valve which is part of the tank venting system. If the bike lays down, the valve closes and prevents fuel from draining from the tank.

It might also be that the fuel pickup itself is no longer submerged.

I suspect the rollover valve won't cause a vacuum in the tank for several minutes of idling, at least.

Actually, it might very well be the rollover valve.

Well, at least at Big Beo (Scarabeo 500GT 2003-2006) there's a special black box called tipover sensor. Who knows if something similar is not installed into ECU?

Yes it's a tip over sensor. Electronic...which is why it's instantaneous, and not at all fuel or tank related.
I believe it is required on scooters sold in USA for several years now.
O.S..

I read somewhere that inside the black box is a metal ball on a curved track. Tipping over causes the ball to roll off the connection part and opens the switch. The ball goes back on track again (closed switch) when the bike is righted.

I've never opened one myself though. And can't seem to find the reference now. So take with a grain of salt.

^^ I don't know about the newer/smaller Vespas, but that's exactly how my Scarabeo's tipover sensor works. Not knowing quite what it was, I had taken the black box off the scooter to look at something else and experienced a sense of dread when I heard something rolling around inside. I assumed it was broken so I took it apart.

I suspect the sensor just sends a signal to the ECU to kill the engine. Less-digital machines might use more mechanical means to do so.

https://www.easyparts.it/Sensore-Ribaltamento-p33609036

Luckily your Italian friend is there to help you ...




Piaggio roll over sensor.

It's generally a self-resolving situation once you put it upright again. Of course the air filter will be soked if the scooter falls on the left side so it's a good idea to remove theemtwo bubbles drain it and if the starting problem persists clean the filter.

Tech question - what does the GTS 'fall sensor' do?

Does it tell you that you fell?

I have a GTS300 - the electronic tip-over sensor is underneath the right-hand footboard. (You have to remove the floor to see it.) Not sure whether the Primavera's would be in the same place, but as I remember mine looks like Attila's picture.

My 2006 Vespa GTS 250ie has fallen over in the snow a couple times while running. It kept on running until I turned it off.

Falling over in snow is better than on pavement...

I think the electronic tip-over sensor is on newer bikes. Not sure when that started happening, though. Definitely!

... the more snow the better ...

Did it try to make a snow angel?

No, but it did try and screw up my back. When did I get old enough that I think about my back before picking up the scooter???