Modern Vespa

So I ran a quick errand before work this morning.. I warmed up the Vespa in the garage, did my errand, and came home. When I started it up to go to work, i noticed that the idle was at a higher RPM... Not super high, but noticeably higher... Then, when stopped at traffic lights, I noticed the idle fluctuating from lower to higher... It would go up, sputter, and come back down. From low idle to high idle to sputter took about a full "one-one-thousand"...

When I got to work, I turned the Vespa off. A few seconds later, I started it back up and it idled normally...

I'm still way under warranty... Is this worth taking into a dealer over? Is it a sign of something else?

Thanks in advance!

Happened to me once maybe six months ago, never before or since. I bet it's nothing to worry about. Shut it off, restart and I see if it goes away.

cheers.

Edit : A year and a half later and it hasn't happened again. This same thing has been mentioned a few more times by other people since this post.

My LX150 did the same thing back when it was relatively new. For some reason I suspected the automatic choke. I don't know what made me think it was the problem but I did. Turns out in my case I was right.

Here's what I did:

Standing on the left side of the bike I looked down on the carburator. There's a large black lump of a thing next to it. That's your automatic choke. The large plastic elbow pops off. You can turn it slightly if that helps get it free. Remove the black auto choke cover and you'll see the unit. On one side there will be a single small screw. This screw loosens the (brass?) ring that holds the whole thing in place internally.

GENTLY remove the screw and GENTLYwork that ring off. Under there is a seal that can come out of its seat. When it comes out of its seat air flows into the sensors and the bike doesn't know whether to idle high or low. ou want to carefully try (with much patience) to realign that pice into its seat and get the ring around it properly so that the ring doesn't come free and the problem recurrs. Please do not over tighten the single screw I mentioned earlier. That bugger is not easy to get to or tighten. But once you get things back in line, the bike should hold an even idel. But if the idle is not completely smooth and even don't worry about it. That seems to have to do with the type of spark plug in the bike. Its the abrupt increasing and lowering of the idle we're talking about here.

Good luck to you. This is how I sorted out what seems like the same problem I had.

Harv

That's a GTS in your avatar, Mr." two wheels of fury"?

So no carb. Correct me if I'm wrong.

cheers

You got it. It's a 250... Fuel injected goodness...

Could be a GT200. Never heard of anyone having that idle problem on an efi bike.

Harv

I stand corrected. So does it have some sort of similar auto choke or not? Because that still sounds like the problem.

Otherwise I'll just shut the heck up.

And leave corrected

Harv

Choke is a carb thing. The ECU sets the mixture for different conditions, and that includes starting.

The non-North American 250s needed an ECU update to solve occasional idle problems or stalling, but apparently ours don't need that.

cheers

So.... Since it's under warranty, I'll take it in and let the dealer take a look?

If you like, but I'll bet they can't find a problem, and I'll also bet it never happens again. Like Harv says , the fuel injection is pretty damn good. Why don't you see if it is a problem, first. And let the fuel pump light go out before starting every time.

Good luck.

i get this on my Gts250ie now and again, usually turning the ignition off and restarting cures it, if not then disconnecting the battery for a few minutes then reconnecting it, starting and letting the engine idle for a full 10 minutes does the trick, resets the ECU, idle may fluctuate during this time as the ECU adjusts itself to the best setting. during the 10 minute wait you can reset the dash clock date etc

if this doesn't do the trick then the sensor in the exhaust downpipe may be loose letting air get in and confusing it, failing that air could be getting in elsewhere, maybe loose manifold bolt(s).

none of the above, possible faulty sensor.

Stock pipe or LV or PM pipe?

Stock pipe.

I over filed the gas tank and excess fuel plogged
the injector housing. I took it into Massimo's Vespa
shop in Costa Mesa and he inturn took it to Eric
Larson USA PIAGGIO who diagoned it
and Massimo took off a
hose to drain and put it back and it ran great
afterwards. If I had waited, It just works its self out without
doing anything. By taking into the shop it
cost me $100 to learn a lesson.
Yardsale 8)

Sounds like the issue I had a couple weeks ago, I reset the computer before taking it to the dealer, my dealer was unable to figure out why it did so.
Sorry I wish I could have helped you. Maybe try pulling the main fuse under the seat and let it sit for 30 minutes and reinstall the fuse, that should reset the computer. If it happens again, Id def take it in to the dealer, but unless theyve run into this issue before or unless they have a computer to plug it into,they may not know what happened.

Good luck

Manny