Modern Vespa

Hi to all. I just joined this forum. I recently purchased a used 2007 Vespa LX150 with 2800 miles. I hauled it directly to a Vespa dealer for safety check/service. They cleaned out the carburetor, changed the oil, and replaced the battery. I picked it up last week, and put some fresh gas (and some SeaFoam) in the tank. I have been riding it, but I cannot get it over ~40 mph. It starts fine, no issue there. It just seems sluggish, especially over 20 mph; it takes forever to get to ~40 mph. I am wondering if this could be an air filter, spark plug, or transmission (belt, rollers, etc.) issue. Or, could there still be a problem with the carburetor? I tend to think not, since it starts fine. Any advice would be appreciated. Thanks.

Welcome!

I'd take it back to where you had it serviced and have them take a look. That said, I'm sure someone will chime in shortly with a suggestion as to what the problem might be.

bump

Howdy! Welcome.

Mine had problems over 8300 ft in maintaining speed.

With aggravating stalling problems that came out of no where I had jets adjusted and carb replaced. Now my Bea works like a charm. Wouldn't hurt to have the air filter cleaned and your lines checked.

I agree with Guzzi Girl, I would also take it back to the shop and let them know you are having this specific issue.

Others will be along soon with suggestions I am sure.

Another one for taking it back to the dealer. Something's definitely wrong. May be something simple but you shouldn't have to try this & that to get it right.

Good luck & happy scooting! 8)

+1 ^^^ I'm not a master of carburettion, but it seems possible that there's still a dirty jet.....faster speed requires more fuel flow.....

Doubt transmission is an issue....it's a bit more all or nothing.

After only 40 minutes of no activity?
Gah, man, a lot of us either work or sleep in late, chill.



If it was mine, I'd be taking out the air filter and checking it's in one piece.
Then clean the carb, then tear into the transmission to get a look around.

Oh, and those tires....

Aloha and welcome to the forum from Hawaii. I have the same LX 150. Twins.Sounds like the dealer isn't that good. Have them reseat the diaphragm on the carb. If it's not seated correctly you won't get above 40mph. Been there done that. I have 48,400 miles on mine. I would also change out the fuel and vacuum lines. Mine last 4yrs tops. As you can see if you keep up with the maintenance they'll last you a long time. I did swap out the carb at 48,000.

I vote with those saying diaphragm or main jet. Did you test ride it before you took it in for the service? How was it running before they worked on it? Welcome to Modern Vespa.

Sorry - I didn't want it to get buried at the bottom

Can I do this myself? Is it difficult? Maybe a video exists?

Front tire was actually ok. Replaced the back tire.

If it's an original, it's way past it's due date. If it's been replaced, you're likely okay. Even with good tread, rubber gets bad.

For your reading pleasure:

Tire date codes

My 2001 Scarabeo still has the original tires. Only 2300 miles.

Sure, 50cc you aren't going any faster than a bicycle. Keep your 150 below 35mph and no problem with that either. Really though, totally up to you.

Cake. 4 screws on top of the carb. Hard part is getting diaphram to stay in place while you reinstall the cover, a little grease helps. May have to repeat several times until you get it right.

Can't hurt to try. As others have said, throw a little grease on the lip and it should seat well. You should also be able to swap out the lines. Good luck

OK - so I removed the carb, took it apart, and cleaned it. It really wasn't that dirty. Re-seated the diaphram carefully. Re-installed. Now, it still starts fine and idles, but when I goose the accelerator, it stalls right out. What did I do wrong?

I'd say it needs a trip to a knowledgeable scooter mechanic.

And here's a hello from one of its 2007 litter mates.

As Madison Sully wrote: clean the air filter first. There are good youtube videos how to do it.

Judy, either that picture is old, or you've done one hell of a job keeping that 49,000 mile scoot looking brand new all these years.

The age is the other key. A 17 years old unused tyre is dangerous too. It isn't wine...

Now it's not just sluggish but stalls?

I have no clue to the problem but I can tell you a Haynes book for your scoot will be great, and save you $, and YouTube videos are great. A good dealership that you can rely on is important and your life is worth far more than the cost of a tire replacement or even 2. It's a nice looking scoot, like that color. And your weight and height can sure matter when it comes to both speed and gas mpg.
Keep us posted as to how the problem gets resolved.

Yes - I have had the carburator out twice. When I reconnect everything, it starts, but stalls when I goose the accelerator.

Lots of fuel related issues can cause that. Have you had the carburetor out AND taken apart? Diaphragm and needle out? Jets cleaned and passages blown out? Needle and float inspected and installed correctly? Is the rubber snorkel from the air filter installed on the carb when you try to run it? Lastly, what condition are the fuel and vacuum hoses in? Everything needs to be installed, tight and correct for the systems to run properly.

First off, Hi and welcome! I forgot about that lovely Plum color!!! I used to have a black '07 150. I miss her dearly. It's a GREAT RIDE!!! So the dealership took care of the 2nd service (200 miles shy) and got you a new battery to help curb potential electrical issues.

Short answer, yes. It could be anyone or all of those factors. My gut says it's probably transmission but a new air filter wouldn't hurt. Spark plug and possibly a new cable couldn't hurt either.

*Edit after reading Judy's post: I don't know what I'm talking about

It shouldn't be rollers because the mileage isn't all the much but it's definitely something to check. People complaining about a low top speed often find the rollers to be the culprit. It's an inexpensive part and not too hard to replace.

JP it gets a lot of TLC. After every ride he gets cleaned and put in the shed. Jack replace the fuel and vacuum lines. Mine last 4yrs max. I'm guessing that's your problem now. Clean the air filter and change out the front tire. While the front tire won't ever wear out it's 11yrs old. I replace mine every 5yrs. You only have 2 tires so having them in good condition is a good thing IMHO.

Pull the airbox off and check that the diaphragm is really lifting when you open the throttle. Try moving it by hand without the engine running scheck that the needle is going up and down with it. Make sure the jets are really clean, run a strand of copper wire through. Check that the accelerator pump is working. With the air box off twist the throttle and see if a mist of fuel is spraying into the carb. let us know if these things are getting it running right.

UPDATE UPDATE UPDATE

Vespa dealer replaced the carburetor. What a difference! Got it back two weeks ago. On the first test ride, I managed to (briefly) get it over 70 mph (albeit, on a slight downhill). However, the most fun is the acceleration from ~ 15 to 45 mph. Such a fun ride! And - I have received a lot of compliments. Thanks to all on the board for your help.

Scoot on!

Thanks for the update and glad to hear you got it sorted out.

Beautiful scoot! Great update - drive safe!