Modern Vespa

Hi All..

I am new to this side and wish to know where do I post technical questions regarding mechanicals on the 2006 LX 150? Is there a technical "only" side somewhere here? Please guide me. Thank you...

You are in it. Ask away!

Hi

Hi....
My wife's 2005 LX150 was laid up for three months while we were on vacation. The gas turned stale..and of course clogged all jets with gum and the battery totally died.
So when we came home it of course wouldn't start. Replaced the battery and gas to no avail in getting it started. Removed the carb and cleaned all jets...orifices..floats...needles for that matter. All seemed to function well and are clean as a whistle.
Started the Vespa and it fired beautifully into idle but died when accelerating the throttle. Removed the carb again and further cleaned it more precisely. Then it finally ran purrrfectly in idle, BUT is has absolutely NO power while running. The best I can do is 30-35 mph. No gunning would increase speed power. What else could there be that is holding back an increase of power. It runs fine in idle and increases in rpm just fine when throttling up.
Any idea what I might have missed. All hoses are OK...all connections are OK....
Appreciate your help

Check the exhaust if the bike was sitting mice can get up there and build nests. I had a bike that made me crazy. I picked it up form a friend that let it sit for some time. The silencer was full of dog food. If you are sure the carb is as clean as a whistle look there. Take it off and give it a shake you never know. Keep us posted on what you do and what the end result is so we can all learn from you problem.
Good luck
Chris

Have you soaked the carb yet, or just cleaned the jets? My next step would be to dismantle the carb and let it all soak overnight, so that it can get into all the little bits.

OK...I'll try soaking it in carb cleaner tomorrow or the day after. This will be my third carb removal. Isn't there anything else in reagard to the vacuum lines? What about fuel pump..is there any or is fuel simply vacuumed via the intake? I don't have a Haynes or similar manual but do have the genuine Vespa shop manual which tell you nothing.

Reagrding exhaust or any obstruction..there isn't any! What about the vacuum chamber cover that houses a long needle pressed down with a spring. The needle sits atop the fast jet..it is clear but..??

ANy of you have ever disected the carb like I did? I removed every part that was removable and still no take off power; only the idle jet seems to power the drive but not the power jets bbeing engaged..hhmmmnnn

Run a tank of SeaFoam cleaner through it.

Just to cover this possibility: could there be water in your tank, getting into the carb, being sucked at full throttle, making it lag in power? Check the next time you take the carb out: keep it upright, to keep any liquid in the barrel, and see if it is all just fuel or not (water will show as a lower layer).

Aloha and welcome to the forum. I would try some seafoam in your gas tank. I keep some in mine and it seems to help. You can get it at NAPA or a store similar to it. The LX batteries aren't know for their longevity I got 2 years on mine and 6 years out of my Piaggio LT150 When i'm away they both don't get used. Good luck

How does it run at max speed? In your case 30mph'ish. Does it sound like it's starving for fuel or air?

In your case, I think the next step is to run the bike without the air filter. If it's okay, you just need to clean it and treat it. Else, it could be the fuel pump not feeding the carb enough gas. Could be the float bowl or fuel pump. Keep pluggin away at it.

Tank has been drained, cleaned and refueled with fresh 93 octane gas. Like I said it idles beautifully; starts instantly without having to give it some throttle. Revs up with no problem....only when riding does it not accelerate past 30-35 mph...even at that speed it does not hesistate..runs just fine but cannot get to top speed. I suspect that the maximum nozzle/jet/emulsifier.. is not firing????

redmomma - if you don't know what to do yourself - take it to a reputable dealer and get them to sort it for you. Really. I'm all for DIY - but only if you can afford the consequences.

Wrecks...excuse my ignorance, where is the fuel pump on a LX 150. I don't see any fuel pump in my manual

jimc...I am pretty mechanically inclined but this simple red Italian Stallion has me perplexed and I feel humilated not being able to find the culprit. I pretty much service my motorbikes as well but somehow cannot find the gremlin in my wifes Vespa..ugh! As for service, Oh, well...one just shut-down here and another is 2 hours away and is just as good as I am. I am not going to pay $500 bucks for Vespa service while one can buy a fresh new carb for $100 US.

Cheers....

There is none on a 2006 model. I believe they added a fuel pump in 2008 in anticipation of the fuel-injected version.

Scratch the fuel pump. I was speaking from experience with carbs on my car. On my rotary engine, I had a similar problem you mentioned. It turned out to be the air filter. But you mentioned you get no hesitations at you current max speed, so I find that kind of weird.

Manuals anyone?....Haynes, Clymer, etc....forget the genuine Vespa manual from Vespa...ain't worth its spaghetti and sauce. Any good downloaded Vespa manuals that you can vouch for?? Thanks...got to get the beast runnin'... Wifes waitin'....weather here still bloomin';....aaarrgghh

http://www.haynes.com/products/sfID1/8/sfID2/105/productID/536
$34

I have no idea if it's worth the sauce!

Good luck with it!

Harvey

Check the condition of the rubber diaphragm at the top of the carb. Also, check to be sure the airbox is sealed. You'll fix it.

Try looking for the workshop guide for your model here:

http://www.wotmeworry.org.uk/manuals/Vespa

This is not the owners manual that came with the scooter.

one of my previous scooters had been sitting for some time before i bought it. the carb needed taking out and cleaning three times before it worked properly. every time i cleaned it out, gunk from elsewhere in the system got in and bunged things up again. i also drained the tank and replaced the fuel line. eventually it ran perfectly, but there was awhile there when i thought it was hexxed.

Hi All...

Excuse my absence from posting my results. I am currently out of town. Will report of any success when I return. Many thanks for your help.

Hi All...

I don't mean to pester you.....I am back from a weekend car away trip. Went back to the Vespa and again removed cleaned the carb for the 5th time. Everything I can think of is OK. Vacuum membrane is fine. Gas flows....etc.etc. Still cannot go beyond 35 mph. I am perplexed....
This lovely scooter has only 635 miles and is NEW....starts instantly but cannot accelerate like before. Hnmmn...since the forum cannot help I guess I have to visit the $$$$ dealer...Thanks all for your input and suggestions, I've tried them all.

CIAO.....

Did you try the SeaFoam?

I am wondering if your variator is stuck. If the engine revs freely on the stand but not under a load, it may be the variator is not changing the drive ratio.

No I did not use any Seafoam as it was not necessary. The tank and lines are clean as a whistle. No sediment or water anywhere.

Variator..hmm...Please educate me about the variator...where is it..can't see it in the manual...However there is no hesitation when accelerating. I think that the max jet does not seem to work in conjunction with the rubber diaphragm>>>but what ails it. There are no holes in the rubber diaphragm. How do I test the vacuum input to make sure that the rubber diaphragm operates under vacuum? I am aware that the rubber diaphragm has a long spring; retainer for the spring and long needle that goes into the shaft of the max jet.. whereas the needle sits into the jets end nipple. I know this needle must be lifted in order to give it a stream of venturied gas when accelerating. Having removed the float bowl and then remove the max jet..thus seeing the rubber diaphragm needle portruding....pushing on this needle by hand really reguires a lot of vacuum to release and by the feel of it, it is a pretty hefty push. Wonder if the spring is too tight? But I never modified anything nor tightenend anything....just opened the whole carb and cleaned it countless times. How much of a vacuum should there be on the port where the clear hose is?
Thanks...

Thanks NIGHTWING...got info on the variator and now know what it is. Seems to be OK. Thank you...