Modern Vespa

Hello,

My new-to-me (and low mileage - 200mi) '20 GTS300 is having starting issues. These first manifested on a stop after a group ride, sitting in the sun for perhaps 30min or so (on a sunny, but not hot, day). I gave up after a few tries and called a tow truck, but after a while of waiting, I tried a few more times and it started, so I rode it home with no issues. Subsequently, it's exhibiting the same behavior in the garage.

The behavior is as follows:
- I hear a whir when I turn the ignition on (fuel pump, I suppose) and all instruments light up and function normally.
- Brake light goes on when I lightly pull in either lever (so probably not a brake switch issue)
- Side stand is up, of course
- when I pull a brake and hit the start button, it will either: 1) do absolutely nothing at all, 2) make a click and that's it, 3) wheezily turn over once or twice, or 4) start normally
- battery is new and reads normal voltage

I did accidentally break off the plastic nipple to which the EVAP hose attaches to the fuel filler at the top of the gas tank - is it possible that this is causing air to get sucked into the manifold or something, given the tank end of the system is just an open hose? From everything I've read the EVAP system is entirely optional, so I'm happy to just remove it if that's likely to be the cause.

In case it's useful, here are a couple videos demonstrating the issue:

Not working:
https://youtu.be/yVwLhlncd90

Turn-on and a successful start:
https://youtu.be/OhHHMKj68sM

That "nothing or just a click and nothing or wheezy" sounds very much like a poor connection in the high current path to the starter motor.

Double check the battery connections, the connections to the starter relay, and the connections to the starter motor, both +ve and -ve.

This is with the assumption that your battery is in tip-top condition and fully charged of course...

Thanks, I will see if I can figure out where those things are (I'm reasonably handy, but not very familiar with Vespas other than adding accessories to my wife's Primavera 150). I agree the path from the battery to starter is where the problem likely lies.

Battery was new when I bought the bike a few weeks ago, and should be fully charged (I wouldn't think it would ever start if it was on the fritz )

"Should be fully charged" - have you put it on a charger after unsuccessfully trying to start, in order to get it back to "fully charged'?

The battery will only support a very few unsuccessful starting attempts before its cranking amps capability falls below what you need to supply the starter's initial stall current.

I'll attach a pigtail and throw it on a charger this morning while inspecting the battery leads, plugs, and starter connections. But given that it does eventually start, I don't believe battery charge could be the issue.

Make sure the charger is meant for small batteries, that is, not one meant for a car or truck. And just because the battery you have was supposed to be new doesn't mean it was or if it's any good. They do fail. Get a multi meter and check the resting voltage.

Yep, it's a tricker charger for motorcycle batteries.

Multimeter test checks out - 13.4v steady, drops to 11 when cranking it. Despite being told it's a new battery, it in fact has "7/18/19" in grease pen on it, so guessing it's not in fact new. Still pretty sure that's not this issue given it (sometimes) cranks right over.

It turned right over and started on the first try this time, however when I revved it a little bit, it sometimes "bogged" rather than spinning up, and seemed to stink more than usual. Fueling issue maybe?

Took to dealer and it seems all that was needed was a map update - seems to be starting and running well (more smoothly than before, actually), fingers crossed that was actually the issue!

What is a map update. Could it be a simple reset by removing battery cable???

It's updates to the parameters that the ecu uses to control the engine. In particular there are 'maps' of numbers sort of like spreadsheets that the ecu uses.

Piaggio makes these updates and only the dealer can install them.

My closest dealer is about 50 miles away. Should I need this done to a 2013 GTS with almost no miles on it??

Don't panic. If it runs well then all good.

Being low mileage i guess it never reached its first service interval at the dealer when it would have probably got an update.

Only drove it 2 miles then did oil/filter change. We'll see how it goes next warm day.