Modern Vespa

In order to catch the gas that often spills out of the fuel filler when I refuel my GTS 300 I cut the end off a 6.25 inch funnel and filed it until it fit over the fuel filler. Now when gas splashes out, it is directed down into the small tray with the overflow drain, and not onto the paint. It works great.

I had bought this for putting windshield fluid in my car and avoiding splashovers.
Comes in a package of two. on amazon (silicone collapsible funnel)

turns out they stretch and fit over the gas filler of the vespa too.

If you are splashing up that high, most likely fuel is running into the evap canister which will eventually get saturated and cause performance and operational issues.

Well then how do you control the height of the splash, it is way better to let the gun cut out the flow than to fill very slow with no visibility and get the gas to come out as the gun does not cut the flow due to too low back pressure. I always wrap paper towel around the nozzle, works every time.

Always fill with the handle part of the pump over the under seat storage area.
This is a well known method and rarely causes any overflow.

I always lift the pet carrier out and sit it sideways across the engine bay. Even safer than placing the lid under the edge

My technique that has worked for me is to put the fuel cap lift and put on the edge of the pet carrier, then to fill up the gas/petrol the first 1.2 gallons fast then I slow down and pull the nozzle out enough and slowly fill thereafter, till I see the petrol then I stop. Generally I end up filling up about 1.7-18 gallons every time I fill up.
It takes a bit of time to slowly fill up but it works.

This is what I also do, I noticed once I let the first gallon or so rip and pull and slow the nozzle I can actually see the fuel level in the black hole.
Also going to try Pepe27's advice 🙏 on the nozzle/handle over the bucket while filing

This. I can let the first gallon or gallon-and-a-half rip, depending on the tank level. Then, I slow way down and listen to full. I spill almost nothing anymore.

I follow the same routine as most of the above. but I also add a short prayer at the beginning hoping I don't spill . Oops I did it again

I also have done this and it was successful. I'm wondering though if it is too full if we fill it until we can see the fuel? Thoughts? I've filled my motorbike this way with no problems.

This is exactly what I've always done, but with the use of those gas pump video screens, the audio from them makes it difficult for me to hear the gas filling up.

Senpai says if you want to top off a bit, go to right when the bubbles start flowing up the neck (around 4:50 mark in the video)

Yes, I've watched Robot fill his tank. And overflow a bit!

Unfortunately, just today a filled up and tried to squeeze a few more drops in and suddenly the fuel was right in the neck! Crap! I've read all sorts of bad stuff about this, yet I obviously couldn't siphon it out.

I know the the gas can heat and expand and get in the evaporative system in this case so the best I could do was ride it on the highway for 70km to burn it off.

No problems at idle when at stop signs and ran all the way up to 110km/hr just fine.

Did I dodge a bullet? Never doing that again, from now on I'll just stop at the click and be done.

There is a petrol overflow pipe in the neck of the filler, so any excess fuel should of drained out through this.

If I top right up at the gas station nearest home I get a little puddle under the LX. Might be from the side stand lean?

Best Practice to put the bike on the center stand while filling up

Best way by far is to know what your bike takes from experience and prepay. I've become an expert and never overfill. Even if you're not completely full who cares. Eliminates the spill and pump slows to a crawl before you overfill if you're are guessing close to what it will take.