Modern Vespa

So, some of you probably remember my tale of woe. Short version is I've spent the last three years chasing a problem with my Vespa. It dies when the weather gets above 80 degrees. It'll ride fine for a while, and then it'll just die and you won't be able to start it until it cools down. The starter works and works, but nothing happens.

I've done a number of things that folks here have suggested, including sparks, jets, evap system removal, venting the gas tank, CDI replacement, spark plug housing...

Finally I duplicated the problem toward the middle of summer for a scooter shop (it was the first time they'd seen it happen in the entire time they had it) and they thought they had it figured. There was no spark when the thing overheated. The spark plug worked, but when the bike was hot it wasn't sparking. That made them think the CDI was bad. They replaced it.

They tell me it's fine, and I ride it for a week, then it dies on me after a stop and go trip down Lake Shore Drive. I talk to one of their mechanics and he says, "Dude, take it to our competitors. We're out of ideas."

So I do. And they're sure they'll be able to figure it out.

A month later, and I just called them. "We're unable to duplicate the problem, sir. We can either keep trying or you can come pick up the bike."

Of course they're unable. They're not gonna go ride it for a half hour, and even if they did, it's now October and cold out, so it may or may not happen at all. So now I've gone an entire summer with a total riding time of about 45 minutes from June to September. I miss the thing, and I'll ride the hell out of it until December, but damn if I'm not supremely frustrated.

Enjoy your scoots. I've sure missed mine.

Were these shops Vespa/Piaggio shops?

Did you try work something out with the sales person who sold it to you (assuming you bought it new...) like getting a different one, extended warranty, etc...

Lemon law in IL?
(although 3 years might be over the limit...)


Sorry to hear of your troubles...

This speaks volumes.

I've had it for 5 years. Not a lemon.

And no, the Vespa dealership in Chicago went out of business in 2004. They sold it to a guy out in Elgin, and I'm not riding an ailing scooter to Elgin to get it looked at. Who knows if I'd make it.

The competitor I spoke of is a newly minted Vespa dealership, but they were open for years before that. It's just that they're only this year (I think) certified as a Vespa dealer.

I'm not saying anything bad about the shops. I fully admit it's a wonky problem and it's not easy to duplicate. Unless you ride it for a long time and it's summer. But what shop has the time to ride around a single scooter for an hour and a half in order to duplicate the problem? I'm sure they're busy working on the fifty other bikes that come through the shop that they can easily pinpoint.

At this point in the year, it's probably not going to be easy at all to get the bike to act up. It's a good bike. I'm just sad it'll be another year before I can probably get someone to even take a look at it with a HOPE of fixing it.

I think I would start taking small bites out of the electrical system. First, replace the lead wire to the spark plug. Then I'd check out the rectifier/regulator, and the CDI by trying (I know this sounds crazy) blowing a hair dryer on each of those parts individually to see if I could replicate the problem. If all those failed, I think I'd replace the wiring harness to see if there's a short somewhere. The harness can't be that expensive, and you can do it yourself.

I'd give them a try. Can't hurt. My LX150 a little slower to respond throttle-wise when it was hot (90 degrees +) outside, and seemed to be better in the cold. Granted, it never stalled on me either, but perhaps you're right in having to wait till the hot weather returns to get the problem diagnosed.

Just looked online and a wiring harness for an ET4 runs about 110 bucks. Which is more than I'm willing to pay for something that might be the problem after I've already paid enough for things that weren't.

Thanks for the thought though. I'll mention it as a possibility next year.

I did. They're the ones that said, "Sorry, we can't duplicate the problem." after a month of trying.

hmmm. Sneaky Len, you changed your post.

I might have a look at the things you mention. Replacing one wire is doable. I just don't feel like replacing a whole system of wires when I've already plunked down so much change on fixes that weren't fixes.

You really feel like a chimp? Or a chump???

Chimp.

Chump implies that I was taken. I don't feel that way.

I just feel inept, and chimp-like. Kinda like "W" only I look less chimp-like than him.

http://www.bushorchimp.com/

To me, the problem says magneto all over it.

See, that's the thing. It says something different to everyone. Even the mechanics.

I only WISH the master of magnetism was making it his personal mission to stall my scooter on hot days. Cause I'm tight with the Juggernaut, and I'm sure he could work something out.

"ow, my hellllllmet!!!! I'm gonna beat-chya Charles! I'm gonna beat-chya WITH Charles!!!"

+1

And if it were the magneto, why wouldn't the sparkplug fire when you unplug it and ground it on the engine block when the bike overheats? The spark is never even reaching the engine.

Wow. So the first 2 years it ran fine? You had a 2 year warranty didn't you

Sorry, no ideas here. Maybe a polite letter to Piaggio USA? You never know what might come of it.... :shrugs:

That's actually not a bad idea. And I've got all winter to wait for a reply.

Yeah, I mean you seem to have tried everything else. Everyone seems to have tried everything else... :shrugs: couldn't hurt right?

If it is the magneto, the plug will not fire when grounded against the engine. The magneto generates and times the spark. It operates with an air gap that is somewhat critical. Too much gap and the spark won't occur. There must be a pickup on the magneto or a connector that connects the plug wire. Any connection should be suspect.

Now, I will issue a disclaimer here. I have not worked on an engine anywhere near this complex. I worked in a lawn mower repair shop when I was in high school. Single cylinder engines back then were very simple, but some of that basic technology still exists today. The parts list shows a magneto, so I am presuming that some of the same principles apply. Of course, I could have my head up my arse too. Gee, it's dark in here.

I feel for you bro. There's nothing more frustrating for a customer or dealer than an intermittent electric problem. I remember the one time at the Chevy dealer I literally had to drive this under warranty Corvette around for literally 2 days straight to get it to have whatever problem it was having to replicate itself.

I'm with Len on the hair dryer idea. Perhaps you could move through the electrical system, heating up things component by component until it dies?

My boyfriend suggests it might be vapor lock. Not sure if you've had that idea tested, but I figured it would be worth mentioning.

Good luck, whatever you figure out. Sucks to have a scooter that dies all the time, I'm sure.

vapor lock exists? I always thought it was like, the boogie man. only uh, for mechanics instead of little kids.

vapor lock wouldn't kill the spark.

How mechanical are you, fubard?
Magnets (as in magneto) will lose their magnatism at a certain temp. Is your flywheel (magneto) getting to hot?
possibly a chaffed wire from the stator that expands enough when hot to ground out.
A bad ignition ground wire?
replacing the spark plug wire and cap couldn't hurt.
Probably gonna have to drop the engine and pull the flywheel and inspect the stator and flywheel.
hell, it could even be the kill switch.

Not very mechanical, I'd say. I'm missing something I think too, I was under the impression that the engine has to be turning for the magneto to be in motion. is that not correct? (obviously I'm even less mechanically minded than I thought)

Since winter hasn't quite hit yet and the thing runs in cool weather...sell it to a schmuck who would have bought a cheap Chinese Scooter and let him think he got the deal of a lifetime. Then buy yourself a new scoot in winter when inventory is good and people are more willing to wheel and deal.

This may seem brutal to some but there is no reason to continue to suffer with this Rubik's Cube of a puzzle without sinking a bunch more time and money into something that isn't a guaranteed fix. JMHO.

Part of the magneto is in the flywheel and yes, it rotates with the crankshaft.

Is the stator different from the magneto? Because I think they replaced the stator about a year ago.

And as for selling it to someone as an unseen lemon, I think I'll stick with the karma I have as opposed to generating new bad karma. I haven't given up on these guys at the newly certified Vespa shop. It's just the wrong time of year to be looking for this problem. Maybe in the interim I'll try the blowdryer idea and see if I can find something.

Thanks all for your input. It's much appreciated. Still, it's always amusing to me that every time I put this question to the boards there's five new things that might be wrong. Just shows what a lame problem it really is.

The stator is part of the magneto assembly.