Modern Vespa

Bizarre. Stuck at gas station around my house.

Bike started perfectly. Battery strong. All the lights turn on.

But the push starter button and nothing happens.

This happened 2 weeks ago and I attributed it to and changed the battery. Clearly not the cause, seems a random thing.

Grrrr.

Update: It then decided to behave and started normally after a one hour or so wait.

Not sure if it helped, but in the meantime I ran back home (1 mile), picked up WD40 spray, ran back and applied it to the started switch, the key ignition, and the seat switch although I think it is sealed).

I don't like not knowing the exact cause of something, it just makes me anxious to wait for the next time the same thing happens.

Only common pattern for the 2 times it has happened is:

1. It is very early in the morning as I go to the gym.
2. ...and I stop to gas up on my way to the gym in my neighborhood gas station.

So maybe moist, coldish (45ish F)? But then why would it start at my place and not after I gas up 5 minutes later?

Weird.

Is the stator / alternator running properly to charge the battery?

That is indeed strange behavior that its twice in a row under similar conditions.

Checking the basic electrical links is defiantly the among the first things to check. There are plenty of forum posts where a corroded switch was the culprit.

If there is any suspicion it might be the battery then carry a jump-starter until this is all sorted out. I like this one, its USB-C, can charge my phone, and has enough oomph to start just about any car. Plus its weather proofed.

https://www.amazon.com/gp/product/B07Z1D26CS/

Does anyone know a good SAE plug to battery adapter for jump-starting motorcycles? The Mp3 has allot of plastic to remove to get to the battery to jumpstart. Amazon has allot of, interesting, adapters that look not so great. There is a combo NOCO Lithium Battery jump-start kit and SAE adapter that looks good, but its also an expensive and banded combo.

An expensive combo for what should be a rare thing to happen
https://www.amazon.com/NOCO-GBC007-Accessory-X-Connect-Charging/dp/B071F36LXZ
https://www.amazon.com/NOCO-GB20-UltraSafe-Lithium-Gasoline/dp/B015TKPT1A/

Did you do the Evap canister removal?
EVAP Canister Removal 2016 series Mp3

When I had the EVAP canister removed I could not start the bike on a cold day, this was maybe a day or two after removing it. In my ignorance I had directly connected the two (now loose) hoses directly together using a hose connector. When I disconnected then individually plugged the hoses the bike ran fine; and still does run fine to this day.

Check the kill switch too. The kill switch is cheap & will not always actuate cleanly
I have a SAE to powerpoint jumper cable which is made from #14 zip cord, works great
I use SAEs made from #10 on all my vehicles, which will carry 30amp, more than enough as long as there is a battery & it's not completely dead
I haven't the switched the alligator clips with SAE, as I have saved a few cars without SAE connectors
I have this https://www.walmart.com/ip/EverStart-MAXX-J309ES-700-Peak-Amp-Jump-Starter-with-Power-Station/217746887?athbdg=L1103
This one has a built in air compressor which is digitally adjustable to within 1/2psi, perfect to get the tire at the exact pressure you want

Thanks for the replies!

All I know it is not the battery or the charging of it. The levels are always super-healthy, especially after the recent battery swap.

I also applied WD40 to the kill switch on top of the others mentioned above... so maybe it is a moisture issue? But then again, why only after a stop 5 minutes into the ride?

My 12k mile service is imminent and I'll make the mechanic research it, maybe he has some ideas. Until then, I'll definitely

(a) keep the bike running if I gas it up early in the morning when going to the gym (same location - poltergeist? )
(b) keep the moisture fighting WD40 under the seat...

Next time I'll also listen closer to the noises the bike makes when you turn the key. I think (but I am not sure) that the few click sounds mean it is passing self checks, but I am not sure if those click sounds are absent when the bike has randomly decided to not start.

wd40 is NOT an electrical contact cleaner or lubricant.

that crap is only good for removing tar spots on cars and sticker glue.

get some LPS 1 for electrical contacts.

and get some aerokroil for penetration fluid.

Pablo, the next time it happens, can you take attention if the red light of the immobilizer is not on? If it is on, can be a problem that the ignition is not reading the key properly, and yes, it can happens not at the first start but after a short/long run (happens to me).

Oh, I didn't think about the immobilizer at all! Definitely will keep this in mind, just in case. Thanks!

May I ask if you have a quick fix whenever that happens?

Pablo, I'm sorry to say no quick fix

I had that problem intermittently a while ago on the 250. Some days starts and could go by without problems, other times I would go out to buy something and then it wouldn't turn on (after turn on easy the first time).

After almost 2 weeks of checking everything, I noticed the light on the dashboard and that it coincided with when the motorcycle didn't want to start, first I thought it was the regular key, but then it did it with the brown key too, so key discarded.

I cleaned the ignition, the fuses, check any broken cable, etc., and it was still the same, so I started searching and found a temporal donor, to check, in the shop from a piaggio that are for a major engine work who I could remove the transceiver from. Problem goes for 3 weeks, then I find the piece from a piaggio destroyed in a junk place and for more than a year the problem has disappeared, so I'm sure the problem was the transceiver that reads the key code.

All the process takes me more that 1 year of headaches and the constant worry about whether or not the bike was going to start.

A simple way, in addition to observing the immobilizer light on the dashboard, is that when this fault occurs, when you pass the key the dashboard turns on, everything seems to be fine, but when you touch the start button nothing happens, literally nothing, and the brake lights come on etc.

Wonder if thread below can help, maybe an antenna wire coming loose or bad contact.

Piaggo MP3 400 - They Didn't Steal It ....

Valve clearance? Another Mp3 500 having trouble when cold is being discussed in this thread.

Hard starting cold

If it's doing nothing as you say, which means not turning over at all when you hit the starter switch, it's not valves, it's not the immobilizer, and it's most likely not battery if you've replaced it.
Have you tried both brake levers when this happens? Is the brake light working when this happens?
Very few things would cause no crank. Which means starter not engaging, engine not turning over at all.

That was exactly it... zero action. Not even a single click of response even with a battery reading (and confirmed at battery connectors) of over 13V. brake light and everything else worked perfectly.

has not happened again...