OP
Thu, 07 Apr 2022 08:12:18 +0000

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Vespa lx50 2007
Joined: Thu, 07 Apr 2022 07:59:33 +0000
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Location: Southsea
 
OP
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Vespa lx50 2007
Joined: Thu, 07 Apr 2022 07:59:33 +0000
Posts: 34
Location: Southsea
Thu, 07 Apr 2022 08:12:18 +0000 quote
Morning all, picked up an LX50 2007 model, with 2500 miles on it. It has had very little use in the last 6 years, just 50 miles. It was struggling to start, and bogging down when revved so i have taken off the carb, cleaned all jets with seafoam (main jet was a bit blocked) and got it started. It ran ok to begin with for 2 mins or so, think the auto choke is working as the idle dropped down after a couple of minutes running. Rode for 1/2 mile and then it started to feel restricted, boggy. Eventually this got so much worse that it stalled at idle and would not rev at all after re-starting. Just ticked over very slowly and died when applying throttle.

Any tips would be appreciated. I have not cleaned the fuel tank out which will prob be my next step as could be years of dried crap in there, but could there be another issue / restriction i am not considering here like the petcock on the fuel tap (not got much knowledge on the petcock thing). I will also i assume need to re-clean the carb too once fuel tank is cleaned out. One thing i didnt really look at or soak in carb cleaner was the actual float bowl itself.

Final minor point, the auto choke was unplugged when i got the bike - which i plugged in and it then started straight up initially. Not sure why that would have been disconnected.

Thanks in advance
OP
Fri, 08 Apr 2022 07:23:41 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Fri, 08 Apr 2022 07:23:41 +0000 quote
I was checking out the vacuum hose last night, from fuel tap to carb. Looks a bit stressed in places, and also has an in line filter on it. It is also clear and not black. Wondering if someone has re-used the fuel line at some point as the vacuum line. I could also get a small amount of fuel out of it when blowing down the hose.
Fri, 15 Apr 2022 13:27:03 +0000

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2017 GTS300 'Beauty'
Joined: Wed, 29 Aug 2007 20:58:04 +0000
Posts: 312
Location: The Netherlands
 
Hooked
2017 GTS300 'Beauty'
Joined: Wed, 29 Aug 2007 20:58:04 +0000
Posts: 312
Location: The Netherlands
Fri, 15 Apr 2022 13:27:03 +0000 quote
With my LX50 4t from 2007, I had the exact same problem, since I replaced my broken vacuum line with a fuel line I had laying around.

When I changed it with a new 'official' Piaggio vacuum line, all problems went away and now it runs flawlessly again. This Piaggio vacuum line is transparant and has the black plastic thing (which I don't know what it's for) in the middle.

That of course doesn't mean that a new vacuum line fixes your problems, I just know it did with mine.
OP
Fri, 15 Apr 2022 14:34:44 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Fri, 15 Apr 2022 14:34:44 +0000 quote
Thanks, I have got it running now, new fuel and vacuum lines, and a new fuel petcock. Only issue now is it will cut out when given full throttle once warmed up although it's easily worked round by not giving it fuel throttle just half and then it's fine. Also is a bit tricky to start when hot. Needs a hint of throttle, whereas from cold it just fires straight up. It's got a red plug cap and does 45 to 50 mph so think it's been tuned or at least de restricted. Also got a bit of noise from the belt drive area, chattering and I notice it when riding too. Maybe this is just the way they am not sure. It's only done 50 miles in 6 years and been sat a lot of its life.
OP
Wed, 20 Apr 2022 11:50:07 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Location: Southsea
Wed, 20 Apr 2022 11:50:07 +0000 quote
Bike has now done approx 80 miles, mostly has run ok. However at the weekend, as i was slowing down to a stop at some traffic lights, it cut out. It restarts, with some throttle, but takes a bit of fettling. Then i ride off, and it did the same again, cut out when i came to a stop unless i kept the throttle open. So, i took the carb off again, and there were some small black bits in the float bowl. This is despite having cleaned the carb twice already with carb cleaner and blowing through the jets. But the bike sat for years without being used. I have not yet test ridden it again, so it might have resolved it.

But a couple of questions - the lights flicker quite dimly at idle. Is this to be expected? I was wondering if a battery that is past its best would cause it to cut out and feel boggy at full throttle. Whilst it is a high powered YUASA battery, and the voltage seems ok, i see some reports of batteries causing stalling.

The auto choke - could this cause this issue too? It doesn't seem to idle much higher at all when it is cold vs when it is hot.

Bike has a new fuel petcock - and other than this issue it runs ok, will sit at 45/48mph flat out, not that i do that all the time of course. It has a red spark plug cap.

thanks
Wed, 20 Apr 2022 11:56:24 +0000

Hooked
2017 GTS300 'Beauty'
Joined: Wed, 29 Aug 2007 20:58:04 +0000
Posts: 312
Location: The Netherlands
 
Hooked
2017 GTS300 'Beauty'
Joined: Wed, 29 Aug 2007 20:58:04 +0000
Posts: 312
Location: The Netherlands
Wed, 20 Apr 2022 11:56:24 +0000 quote
Quick reply on the flickering light at idle: that sounds like your idle is too low. When you place it on the centerstand (and the engine is warm, like it has run for about 10 minutes), adjust the idle screw so that the wheel just doesn't spin, or spins a very very tiny bit.

Maybe that'll solve the cutting out problem too.
OP
Wed, 20 Apr 2022 12:04:38 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Wed, 20 Apr 2022 12:04:38 +0000 quote
Yep, have adjusted the idle speed. The rear wheel creeps slightly forward when it sits at idle. Sometimes it will sit and idle fine, for example i left it after a run the other day for 5/6 minutes, and it didnt cut out. Yet later that day, it will idle, and slowly the rpm reduces, and then it eventually the rpm gets lower and lower and it can't keep going and just stops when the idle gets slow.

For me, this points to the idle jet being a bit blocked by that black stuff in the float bowl. As when i was out riding, it would either keep idling, or just cut out when i came to a stop, presumably when it switches from the main jet to the idle jet. I assume that when it is sat idling, there is suction in the float bowl, as the fuel is drawn up through the idle jet.

However, i could be wrong so looking at other options too. I have also cleaned the air filter although i dont think it is that as it is intermittent. That is why i wondered re the battery. But then it isnt slow on the starter button, turns the engine over fine.
Wed, 20 Apr 2022 12:08:56 +0000

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2017 GTS300 'Beauty'
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Location: The Netherlands
 
Hooked
2017 GTS300 'Beauty'
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Posts: 312
Location: The Netherlands
Wed, 20 Apr 2022 12:08:56 +0000 quote
If you have a Volt-meter you can check the battery. When not in use, it should be at least 12.4 Volt. When pushing the starter button, it shouldn't get below 9.6 Volt.

At least this way you can eliminate the battery.
OP
Wed, 20 Apr 2022 12:12:29 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Wed, 20 Apr 2022 12:12:29 +0000 quote
Showing 12.6V on volt meter, and drops to 11 something when pressing starter button. Battery is only a year old, although not had much use, if any in the last 12 x months.

I will see if the carb clean resolves it, it does seem like it is something intermittent, which would point to the debris in the carb. Sometimes it will block the jet, other times maybe it doesnt.
Wed, 20 Apr 2022 12:17:19 +0000

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2017 GTS300 'Beauty'
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Posts: 312
Location: The Netherlands
 
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2017 GTS300 'Beauty'
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Posts: 312
Location: The Netherlands
Wed, 20 Apr 2022 12:17:19 +0000 quote
With those readings the battery seems fine to me.

Maybe your stator may be at fault, but that's something the Greasy will probably have a lot more in depth knowledge on than I have.

I don't believe that auto choke is the culprit. It will stop choking after a couple of minutes and if it doesn't, your RPM's will be higher instead of lower. Also, if it doesn't choke at all, the problems will arrive in the beginning of your run, not when the engine's hot.

Finally: do you know if you could see light through the idle jet when you cleaned it? If I'm not mistaken, you have to be able to see a very very small hole, when looking through it into a light source.

Anyway: let us know how the test run went!
OP
Wed, 20 Apr 2022 13:01:52 +0000

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Vespa lx50 2007
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Location: Southsea
Wed, 20 Apr 2022 13:01:52 +0000 quote
I could see light after i cleaned them out. There did seem to be perhaps a slight blockage but the pin hole is so small, its hard to know. But either way if the dirt was being pulled up into the jet, it would cause an issue i am sure.

Will let you know how i get on! Thanks for the tips
OP
Wed, 20 Apr 2022 14:14:54 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Location: Southsea
Wed, 20 Apr 2022 14:14:54 +0000 quote
Mopmed - where did you get your vacuum line from? Mine also had the black one way filter / valve fitted to it, but i replaced the line with some other hose and took that valve out. I don't think it is the cause of my issues as it was other running ok for 50 to 60 miles. But i might look at getting another hose anyway, and one way valve. I have used some transparent hose, but it has a smaller diameter than the fuel hose (this is intentional as the nipple for the vacuum hose is smaller than the one that for the fuel)
Fri, 29 Apr 2022 11:16:41 +0000

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Vespa Lx125 4T Leader 2008
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Location: Barcelona
 
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Vespa Lx125 4T Leader 2008
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Fri, 29 Apr 2022 11:16:41 +0000 quote
Thank you for sharing. Pictures would be awesome don't you think?
OP
Mon, 02 May 2022 06:07:43 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Posts: 34
Location: Southsea
Mon, 02 May 2022 06:07:43 +0000 quote
Not sure whether to get a replacement carb, or just buy a kit. Bike is running and runs fine for 6 or 7 miles but then starts to cut out sometimes after a full throttle run, and also when giving full throttle at idle it will die, so need to use up to half throttle and then once it's moving seems fine to use any amount of throttle.

It needs a new float drain screw as the o ring is not sealing as it leaks fuel from the float bowl drain, and also the actual float bowl gasket is also leaking. Would I be better to get a replacement carb do you think or just those 2 parts. As I'm not sure if the auto choke is working properly, I wonder if just buying a complete carb off ebay with the auto choke would be a better option.

Anyone have experience with those cheaper carburettors? Thanks all.
Tue, 03 May 2022 13:53:24 +0000

Enthusiast
2007 LX150
Joined: Tue, 10 Oct 2017 17:10:42 +0000
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Location: Washington DC
 
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2007 LX150
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Location: Washington DC
Tue, 03 May 2022 13:53:24 +0000 quote
You may be better off just getting a new carb. By the time you replace all the rubber bits, screws, gaskets, slide, etc, you're almost close to the cost of a new carb. Suggest not getting an aftermarket one and sticking with OEM. I've done both before, and spent so much time fiddling with the aftermarket one to get it running right (which it never really did) that it didn't seem worth the money saved in the end.
OP
Tue, 03 May 2022 14:09:12 +0000

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Vespa lx50 2007
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Vespa lx50 2007
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Location: Southsea
Tue, 03 May 2022 14:09:12 +0000 quote
Thanks - i was leaning towards that, but having been out a few times since my post, other than it stalling at idle (i can replicate the condition - once it is fully warmed up, full throttle for 10 seconds, ride 50 metres, then throttle completely closed, and brakes on. As i come to a standstill bike cuts out (unless i give it a bit of throttle to keep it running). Have fixed the leaky drain, so it really is only this idle issue and the float bowl gasket. Am tempted to adjust the idle mixture screw as it does "hunt" at idle sometimes, revs up a bit, then down, then back up.

I will look into genuine carbs too - good shout, maybe aftermarket is not the way to go
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