Modern Vespa

Hey everyone,

So I have been out and about on my 22 GTS 300 and its been cutting out when stopped, however when the bike cools down it will start.

A few things I have noticed,
- only does it when hot,
- the pump doesnt prime when hot.
- it doesnt cut out when riding only when you stop(not oil pressure)
- once cooled down it primes and starts.
- doesnt do it in the colder climates.

maybes- Fuel pump.
- ECU.
- HT lead.

any ideas?

Fuel pump!

Can you hear the fuel pump whirring when you turn on the ignition? If not, 100% fuel pump with thermal problem.

Warranty?

The fuel pump primes first up in the morning and when its cold then cuts out to start, however when it hot after riding for a while and you stop and turn it off it will not start at all.

The fuel pump must whir every time you turn the ignition key to ON. If your Vespa does not start when it is warm/hot and you do not hear the whirring beforehand when you turn the ignition key, it is due to a thermal problem with the fuel pump…

There has already been a recall for GTS from the 2021 model year.

Cheers, i have been on the net and cant find the recall anywhere?

Check date of manufacturing (QR-Code on the inside of vehicle under pet carrier).

Check Vespa gts 300 brake issues (Post 2631273)

Your dealer should be able to run your VIN for any recalls. I own a 2021 and the fuel pump has been replaced. I never had any issues, yet it was the recall so it happened.

So new fuel pump has arrived. lets see how this goes.

It's mindboggling that Piaggio has had so many fuel pump issues with the GTS since 2006. One would think they figured out the problem after the first round of recalls.

For sure they found the problem but i dont think they took action to solve it.

Probably the purchasing unit ordered millions of these for less than 5 euros.

So the unit i take out im going to replace the actual electric pump with after market and see if it works.

Fuel pump is a known fault in 21/22 my scooter is 22 so start at the known then go from there.

Have you overfilled with Gas recently? and do you have the EVAP installed (comes on USA bikes)

Had this happen to someone in our group same model and year, turned out it was Vapor Lock from the EVAP system -- happened to him a few times, we took off the EVAP (was full of gas) and it never happened again

If you search there are a bunch of posts about it on here

I posted about how to remove here in this topic > GTS Check Engine Light

Well.... i replaced the fuel pump relay and went for a ride in 30deg heat then left my scooter parked in the sun for 30mins I tried to start it and no pump prime and no start. So i cooled the scooter in the shade for 30+mins and rode home. I have now replace the pump and replicated the ride with no issues i have been riding now for three day with no issue.

So thank you to all It was the pump however the Vespa importer for AUS has failed to acknowledge the issue and life goes on.

Hello!!

I am two years and 11,000 miles into my GTS but in the beginning at around 600 miles the same exact thing happened…….fuel pump was replaced. Then fast forward one year later it happened AGAIN!!!! I was so upset…….but now after 2 fuel pump replacements all has been good for one year of daily riding. It was so scary for me. I ride to and from NYC daily and on my way home going over the busiest transit bridge in the world is when it happened to me second time. Luckily I was in the right lane and able to pull over.

I forgot to mention I have got myself a 2018 fuel pump NOS so that's a spare if this happens again. I am now using the Vespa fuel housing and a aftermarket pump so I will see how this goes. I also notice the pump pressure releaf valve in the top of the housing was pointing the wrong direction so I corrected that before it went back in.