Modern Vespa

Hi. New member. I appreciate your patience, and yes, I searched…

Son-in-law is stationed out of country and found the subject scooter in June 2024 at a great price with 800ish miles. I bought it, picked it up, and am storing it for him until December 2026.

I added Stabil and ran it. Siphoned out as much fuel as I could. Put on the battery tender. And it sat. Now it won't start.

What I've done:
-Used fuel pump prime to force out the rest of the gas
-put in about a gallon of new 91 octane from a brand new can.
- added Techron cleaner (an appropriate amount)
-again using the pump prime, ran about a quart of the new gas and Techron into a jar
-cleaned the injector several times with carb cleaner
-watched the injector spray. It was a weak shot of droplets.
- cleaned and dried the spark plug
-tried starting fluid (ether) into the rubber boot between the air box and throttle body. It will idle as long as the ether sprays
-setup a rig to blow carb cleaner through the injector using a 9v battery turned off-on-off quickly. Improved the atomization significantly.
- now it will start and idle very roughly for a bit and die. Giving it full throttle, it will run but won't rotate the tire fast at all.

I have an injector arriving soon that will likely be the next step. I don't know the likelihood that this will fix it.

I've read enough to know that I won't be DIY pulling the tank to change the filter sock or inline filter.

Any suggestions and steps besides "don't ever let a Vespa sit with fuel in it"?

Do you mean while on the stand? You must disable ASR first.

It's running so poorly that that tire rotation speed is really inconsequential. The idea that it takes full throttle to keep it running is the key.

Having said that, I'm not sure what ASR is, does, or how it impacts this fuel-related damage / condition?

Thank you for taking the time to reply.

Have you tried running it on gasoline, and not some exotic potion you've conjured up? Not the ethanol free scam, just regular top tier premium right out of the pump from a name brand station that sells a lot of gas?
That's what they are designed to run on.
I do agree that it's probably the ASR that's the issue as far as running on the center stand.

ASR will not affect idling on the stand.

ASR will affect turning the throttle on the stand. I'm think you said you did that.

I'm not offering a solution to your overall problem, just a tip when testing.

As to the exotic concoction, yes… 91 octane as I mentioned. In a new can. From a popular gas station. The 2-3 tablespoons of Techron were added afterward.

Thanks for the tip on the ASR. I now understand how that would impact reviving the throttle on the center stand.

Any thoughts on how I might cure the poor idle and dying, beyond replacing the injector? Or instead of replacing the injector? Any stories of cleaning the throttle body, or exotic concoctions that would clear gunk from the fuel pump, or free a sticking check valve, if that is a possible contributing factor?

Ride it.

You already have a new injector on the way, may very well fix it. If it doesn't run a couple tankfulls through it with the Techron, should dissolve any remaining gum.

The injector fixed it! Thanks all for the assistance!

Should still ride it, just so it doesn't happen again.

Agreed. I rode motorcycles for 15 years and stopped due to all the distracted drivers.

I've considered jumping back in but I don't really need to at my age. I've been not riding his Vespa as I didn't want to feed the fire, but I guess a few laps around the neighborhood won't hurt.

I haven't gotten used to the width of the floorboard, and I still try to press down with my right foot, which is pretty ineffective for stopping.

Please change the title of your post to ***NOW FIXED***. It saves people from reading through the whole thread only to find the issue is now solved.

You could get yourself an older Vespa having rear brake with foot

I still do that on occasion and I've had my GTS for nearly 5 years now.