Modern Vespa

Hi everyone,

I own a 2022 Vespa GTS 125, and I've recently encountered an issue that has happened twice now under similar conditions. I wanted to ask if anyone else has experienced this and what could be causing it.
The Situation:

I was riding to Ağva (long ride with some hills and open roads).
On my way there, the wind was at my back, and everything seemed fine.
However, on the way back home, the wind was strong and directly against me.
Because of this, I had to keep the engine at higher RPMs than usual to maintain speed.

The Problem:

Around 30 km from home, I noticed the check engine light turned on.
I didn't feel any loss of power, and the scooter ran fine.
However, I also noticed that fuel consumption increased more than usual.
The last time this happened, I had also refueled from a different, unfamiliar gas station (same as this time).
The check engine light disappeared the next day after letting the bike rest.

Possible Causes?

Could riding against strong wind cause the ECU to detect a lean mixture due to excessive air intake?
Could it be related to the fuel I purchased from an unknown gas station?
When I opened the fuel cap, I heard a noticeable "pssst" sound, like vacuum pressure being released. Could fuel tank ventilation issues be contributing?

Has anyone else experienced something similar with their Vespa GTS?
I'd love to hear your thoughts and possible solutions. Thanks in advance!

I'm assuming your 125 has the emissions carbon canister fitted (AKA Evap Crap) which is inline between the tank vent and the intake manifold. This can get clogged with fuel if you overfill, or ride on bumpy roads right after filling such that fuel gets into that vent.

If you have regular emissions tests to keep the bike deemed roadworthy, then leave well alone - if not, you can remove this system entirely, adding an extra vent tube from the tank, around to the left hand side, then down to dangle above the ground. The tube to the inlet manifold should be cut and sealed - an old bolt screwed in works fine.