Modern Vespa

Hi,

My son and his girlfriend just delivered an LX50 to my house, hoping I can get it running. I don't know what year it is. Her mother bought it on a whim at least 5 years ago, drove it once, and hasn't been able to use it since. They say it will start but then dies after a few seconds. I've worked on quite a few cars and trucks but never scooters or motorcycles. This sounds like a fuel delivery issue to me. The battery is dead so I haven't tried to fire it up. I think I'll drain the old fuel out first unless they can tell me it's fresh. The manual says: "The vehicle is equipped with a fuel valve and a starter which switch on automatically
as soon as the engine is started." That makes me wonder if there is something wrong with that valve. Here are a few pics.

Greetings:

Nice scooter. I have never seen a color-matched rack before.

Vintage 2007 LX will have a gummed-up carb which will need cleaning. Google scooterWest YouTube for process.

I just finished up an LX 50 project and had a lot of fun, despite the shortcomings in my technical ability. You'll definitely have fun with it, they're solid bikes.
I'll second Wheelman's comment regarding the ScooterWest videos. That's how I learned how to do pretty much everything on my LX.

Check the fuel and vac hoses to be sure they are solidly connected, check to ensure the rubber intake boot is intact with no cracks. Then pull the carb jets and clean them. This should get you to the point where it will start and run and not stall out on its own. If it will warm up and you can ride it around but it will die at random, be advised these have an ignition box (called CDI) that had a high failure rate from the factory. Beyond that, check the plug. It's next to impossible to access, but with just the right socket (has a 19mm hex on the end that you can turn with a box end spanner) it's frustration-free. I use the OEM TOOLS 22887 purchased from Amazon for $10. Well worth it. Makes a job everyone complains about easy like it is supposed to be. Valve adjustments are also very easy to perform on this machine, but I'm almost 100% certain they are not so out of spec as to cause what you're experiencing. I'm pretty sure it's just a gummed up carb like Wheelman suggested. Also don't take that manual too seriously, it's making the scooter sound a lot more complicated than it really is. It's a very simple carbureted single cylinder engine, just a tad more sophisticated than a weedeater. You should find the factory shop manual PDF somewhere on the web which will help somewhat but again be advised the Italian to English translation isn't super perfect and will leave you scratching your head sometimes with the way they communicate.

Great Scooter Acquisition!

Also check the air filter. By now it is a disintegrating mess if it hasn't been replaced.

You may find that removing the airbox cover has one screw that is a PITA to get at. It sort of looks like the factory tried to put a hole in the body for a screw driver to get at the screw but they missed...at least on the scooters I have had. I buy one of these to put in it's place.

https://scooterpartsco.com/vespa/lx-50/lx-50-air-and-fuel/air-filter-knob-screw-479132

You will have one already but using these in the top two airbox locations makes life easier for me.

As far as the sparkplug access I have heard from a couple people how hard it is to get out but its not an issue if you have a swivel head ratchet. The tool is indispensable if you haven't used before. I can recommend a Great Neck Brand #28098

https://www.skygeek.com/ats-11076-swivel-head-ratchet-3-8-drive-8-3-4.html

and a nice 5/8 spark plug socket works great to R/R the spark plug. I can recommend a SK #4420 if you do not already have one.

Thanks everyone for these helpful welcoming messages! I'd give them a thumbs up, but I'm still a "lurker" (less than 5 messages) so I can't do that. I'll work through these suggestions and report back.

That ratchet head will NOT fit to remove the spark plug. Not even close to having enough clearance. A low profile ratchet head won't even fit. Need a socket like the one I mentioned which is the perfect length and has hex flats on the end so you can use a spanner to turn it.

However the SK spark plug socket looks OK to use, it has hex flats on the end and appears to be a good length. It's $7 more than the one I suggested though.

The ratchet and socket combo works really well for this era LX50. I just used it to R/R my sparkplug! You put the socket on the plug first and then working from the top you attach the ratchet. I'm not quite sure what your clearance issue is but no problem on my scooters. I have a 2009 and a 2007 LX50. If I have time later I will post a picture for you.

Would you expect lights on the dash to light up if the horn is working? I'm getting no sign of life from this thing except the horn. I thought the battery was completely dead, but the horn surprised me and sounds loudly. I would expect that to take more juice than the dash lights. I have a 6 and 12 volt charger, but the manual makes charging these batteries sound like rocket science.

It's also stinking up the garage with a gasoline smell but no sign of leaks. Is there a gas vent that would normally cause a garage to smell bad?

The lights come on when it's running. The brake lights should come on when the switch is on. The battery is just one screw away. Open the seat, in the back of the compartment is the battery cover. The screw is on the left side. Unscrew it and there is the battery.

Definitely clean the carb and drain the fuel. The fuel valve or petcock is vacuum activated. Replace the fuel and vacuum lines. Spark plug is just tricky. Watch some scooterwest videos you'll figure your way around in no time.

If it's been sitting a while, you are probably going to need a carburetor. The passages on those little carbs are easy to clog. There are people who claim you can get a cheap carb off the internet and make it work. I've ridden a few like that, but I've never rode a Vespa with a chinese carb that didn't have a big dead spot in the middle or stumble when you open the throttle. Plan on Carb, fuel valve, fuel line, vacuum line, air filter, and probably some odds and ends to get it running right. Check to make sure the intake manifold and boot from the air filter aren't rotted. Don't start on the laundry list that seems to pop up whenever anyone comes up with an old bike that's been sitting until after you have it running like it should.

Here's what we have for the Vespa LX 50. You have a two valve model. Send an email if you have any questions.

https://scooterpartsco.com/vespa/lx-50

Thanks. Yes, I know where the battery is and have already removed it and put it back once. What I meant by rocket science is that you apparently have to regularly check the electrolyte levels and for charging, the manual says: "THE BATTERY MUST BE CHARGED WITH A CURRENT EQUAL TO 1/10 OF THE
RATED CAPACITY OF THE BATTERY AND FOR NOT LONGER THAN 10 HOURS." (The all caps is from the manual, not me.) I just don't know if I can use my regular 6/12 volt car battery charger or not. I have to research what current it actually charges with. I watched some of those videos last night. That guy (Robot) does a good job. Thanks again.

I have a 2007 and there is no way I could fit a ratchet head on the socket. Your socket must be a dimension that allows it somehow, like a little shorter perhaps. But those swivel head ratchets are not low profile in the least. Take a photo or three.

Should the fuel gauge function with the key turned to ON but the motor off?

I figured out the fuel smell. The people who brought it to my house laid it on its side and fuel leaked out onto the seat. Arghhh!! Hopefully it will fully evaporate as the garage warms up and not permanently damage the seat. I think all the fuel might have leaked out, which is why I am asking about the gauge.

Your tripping me out Booger. What kind of swivel head ratchet are you using? I am pretty well trained on quality tools since I built fighter jets in a previous life and I'm telling you that the Great Neck ratchet I mentioned in an earlier post is an absolute must in any mechanics tool box. You can throw all your other 3/8 ratchets away once you have this baby but I digress. Very nice in the 1/4 inch drive size too!

Anyway here's my approach.

Spark Plug Removal:

1. Remove the forward facing cover in the footwell area.
2. Remove boot on spark plug.
3. Insert socket into the hole and onto spark plug
4. Snap ratchet onto the socket
5. Loosen spark plug (couple turns is all)
6. Remove ratchet from socket. (You push a button on top of my ratchet and socket is free)
7. Use fingers from front and top to turn the socket and get the plug out.

Installation is reverse.

The only thing that I can maybe see that is causing any propblem is that some of you guys do not have compact enough sockets? The SK brand one I mentioned earlier is 2.375 inches long but I also have a vintage Craftsman 3/8 drive 5/8" socket #43324 that I see is still available. It's a bit shorter so well suited for the task.

https://www.ebay.com/itm/Craftsman-43324-3-8-Drive-6pt-SAE-5-8-Spark-Plug-Socket-USA-New-/124596487459


Good luck and let me know if I may be of any further assistance.

The gauge only works when the motor is on. It may start to indicate while the starter is turning over before firing if you really dont know if there's fuel.

Nice. My dad did that same thing when he was a working man. The reason you can get that swivel head ratchet on there is your socket is just the right length to make it work. My socket is just the right length to get a 19mm box end on it. All I do is break it free, take the box end off, and twist it out by hand, reverse on the install. So both our methods are sound. Mine's cheaper though!

The vacuum line on the fuel tap had a big hole in it near the tap. I clipped the end off and reattached properly. I figured it would fire right up. Nothing. I took the vacuum and the fuel line off the tap and nothing leaked out of the tank, which is a good thing. I cranked it over with the line off and fuel squirted out the tap, also a good thing. But still absolutely no sign of life when trying to start. This is contrary to what I was told about the scooter. They said they could start it and it would run for 20 or 30 seconds then die. That sounded like it ran OK on choke but then died because the middle jet is plugged. But this doesn't even give a hint of wanting to start. I tried to remove the spark plug to check for spark and a wet plug but don't have the right tools. The little kit that comes with the bike is a joke! It has a "socket" that does fit on the plug, but the other end of the socket just has holes in the side, as if you are to put a screwdriver through and turn it. But it goes too far into the block to access the holes.

If you're wondering why I haven't already removed the carb and cleaned it, it's because of what I was told by the people that own it. I wanted to hear it run and then die before digging into the carb. But if I find out I'm getting spark, I guess that is what is next.

It takes a crazy long amount of time to prime the float bowl area with fuel, if it has dried up. You have to open throttle all the way up and wait for ever if going on electric start. You might try 20+ kicks of the kickstart with fully opened throttle first. You scooter might be fine.

That's good to know. I didn't try for too long because I'm always worried about killing the starter or battery. I also didn't have the throttle all the way open.

You can always pull the vacuum line off of the intake and provide your own vacuum to it to prime the bowl. No need to pull the spark plug to check for spark. Pull the cap and put a spark plug in and check that for spark.

That's a good idea. Do you think an automotive spark plug would spark?

I'm about to give up on this POS. I think it has multiple overlapping problems. Sometimes nothing happens at all when I hit the start button, radio silence. Other times it cranks over super slowly, like one turn per second, as if the battery is about dead. Other times it turns over and spins like a champ, although still not showing any sign of starting. I think there are electrical problems, and that's not something I signed up for.

You need to want it to work and that is going to require some time and/or money to get it sorted. You could get a 22 dollar cheap Chinese Keihin carb and put it on there to see if the carb is the issue. You will want to fix the old one and re-install though because those knock off carbs are not as nice to run as the OEM stuff.

Did you take off the airbox cover yet and check if the filter is a gummy mess?

You will still have oils to change before you start using her...and a brake line flush.

So you can do all this stuff yourself and work through the process or maybe find someone to bring it too. I live in a remote outpost so that is not always an option but for you? There must be some choices.

How many miles are on the thing?

Yeah, I know, it takes time and money for these things. It's just frustrating because I am trying to help the owner get this running, and I was told that it started fine but wouldn't keep running. If figured I could diagnose and probably fix that. But then they bring it over and nothing works at all.

I have not done the air filter yet or changed the oil or other maintenance things that need to occur before this thing is used, and I don't plan to do those things unless it shows some sign of life. I don't think a clogged air filter, for example, would cause the motor to turn over sometimes slowly, sometimes just fine, and sometimes not at all. I did take the spark plug out and it didn't look too bad - just a bit oily.

It only has 3,400 miles on it, but none in at least five years.

Appreciate all the help. Sorry about whining!

So the workshop manual I found online said the LX 50 should have a 12V 4Ah battery. I found a user manual for the four-valve version of the LX 50 and it says the battery should be a 12V 9Ah. Someone in this thread said that I am working on a two-valve version of the LX 50. The battery that is in it is a 12V 9Ah. Should I be concerned? Also, this battery appears to be one that requires maintenance. It has fluid levels and caps that appear to come off. You can see in the picture that it is overfilled except for one cell. I've never had to maintain a battery before. Can this be swapped out with a conventional sealed battery that doesn't require maintenance? I'm thinking about sending the owner of this bike on an errand to get a new one or to verify that this one is actually working.

I think the higher capacity battery (9 Ah) is fine - the only concern is physical fit, but it must be alright if it's in there now.

Yes, you can swap it for a sealed battery of same size and capacity.

If you're trying to troubleshoot the bike, you definitely want to be sure you have a good battery to start. A bad battery can lead to intermittent and confusing problems.

You haven't gotten it running yet? Get a good battery. Borrow it from your lawnmower or something. As long as it's 12V it should work to run the starter. Don't concern yourself that it exactly matches the battery spec in the Vespa owner's manual. If it's 12V who cares what the Ah is. You need a solid 12V to spin that starter and eventually start the engine. You can then go from there. It appears you are expecting the flaky battery that's in it to just wake up and work. I think the battery is trying to tell you it has other plans. Use a portable jump cell even.

You wouldn't be the first person to suffer dead battery denial. Turns over one minute, won't the next. Classic sign of a battery that no longer wants to do its job and should be replaced.

Do you own a multimeter? A battery charger? I thought you said you worked on many cars? The principles are the same.

That is frustrating! I mentioned the air filter as a must check now based on the condition of a couple I had. They were absolutely breaking down into an oily powder and I was worried that I would introduce that stuff into the carb or engine which would further complicate trouble shooting. I know it doesn't suck air like a 40 valve V-8 but I wanted to eliminate that from the risk tree. Oh!! So worth saving! Lets get cracking.

I've worked on cars ranging from 1942 to modern and none have had this type of battery that you have to add water to, and I've been lucky not to have to deal with many electrical problems. Yes, I have a car battery charger, but the manual for the Vespa has detailed specs and warnings about charging so I was afraid to use the car charger on it. The owner sent along a charger and said he used that so I did, but still not sure if it is an appropriate charger. The battery made crackling noises while charging. I've never heard that before in a car battery but maybe that's normal for these unsealed ones. I do have a multimeter but I didn't know that shows the charging status of a battery - I just tested and it says 12.3. As for the Vespa, it just makes a click noise just under the seat now when trying to start, much like a car does with a dead battery - but the sound seems to be coming from quite high, just under the battery, and not down by the starter. I have a spare car battery that I know is good, could I connect that up and use it to troubleshoot the other problems?

I don't think 12.3 is sufficient. For cars, I think it needs to be 12.6 or higher to be healthy enough to start

In a conventional battery (Lead-Acid), like you have, there are individual places in the battery to put in de-ionized water and they have to be maintained. On the outside of the battery there are high-low marks for the water height. Are yours ok? You can pop off the top cover and unscrew the fill ports to see better. You can get de-ionozed water in some grocery stores in the water section. Good Luck!

Yeah just hook that up somehow. Might need extension leads. The type of battery you add water to (unsealed lead acid) has been used in cars for years and years and years, only to be superseded by sealed/AGM then lithium etc. I can't believe you have never encountered this type especially if you have done work on cars from all the way back in the 40s. Extremely common battery type, nothing at all special or unconventional about it.

Don't charge if it makes crackling noise! Just get a known good one and go from there. I suspect it will then turn over reliably but probably won't start. The carb is very likely to be gummed up in several internal locations by now. If you have an ultrasonic cleaner you should just completely disassemble it and run the parts in the cleaner for a few cycles, plus manually reaming out the main and slow jets with a length of a single conductor from some copper wire. Use some fresh gas and you will likely get it started and may just even keep it running.

My guess is there is nothing really wrong with the engine it only needs maintenance from lack of use.

then you weren't working on 1942 cars in 1942. All the bikes I remember from the 1960s had this sort of battery, and occasionally you would get the drain tube misrouted and damage some metal with acid. If the battery is making a crackling sound when it's charging, you seriously might want to stop charging it. And the clicking sound is the solenoid, that little square thing that plugs in next to the battery. You can use a set of screwdrivers to bypass it and see if the starter motor will turn.

It sounds like you have a manual for a two stroke version, which is a completely different engine that only needs 4 amps to turn over.

Here are links to the two manuals I found. The first one is the one that says 4 amps. The second one is for a 4-valve, and I think you told me I have a 2-valve.

http://www.vespaclubusa.com/manuals/vespa_lx50.pdf

https://cdnmedia.endeavorsuite.com/images/organizations/05211b9c-b6c7-4840-8e84-2970c2318c24/LX%2050%204V.pdf

You are correct! I've been thinking about it, and all the old cars I've worked on either came with no battery at all or one that obviously needed immediate replacement. I realize this isn't an unusual battery and was the standard for cars back in the day, I've just never dealt with one. I read more about them and a crackling noise is not unusual when charging. In any event, we took it to Interstate Battery and they said the battery is 100 percent fine. So it's back on the charger and I'll see what happens tomorrow.

In the meantime I checked both air filters and they look mint. I also noticed that a clamp is missing on the intake, which may explain part of the problems with how it runs, but obviously isn't the cause of this starting problem. I found a good video explaining how to test the starter relay and other parts of the starting system and will work through that if the problem remains.

I ran through the tests up through 5:28 in this video: I think the starter is shot. With a fully charged battery, I got good voltage between the negative terminal on the battery and the starter relay terminal that is connected to the positive terminal of the battery. I also got good voltage between the negative terminal on the battery and the other main terminal on the relay when hitting the start switch and holding the brake. I also jumped the relay completely and tried to start and got nothing. So with all that, and a fully charged battery, and clicking at the relay, it seems like it is the starter, a bad connection between the relay and starter (it looks good from what I can see), or a bad engine ground. I can't find any other engine grounds. Does anyone know if there is one and where it should be? Thanks!

That's a good video. If you have been working through the video you are getting really familiar with the scooter and that is a good thing too. So you haven't heard a cranking sound yet right? Looks like a new starter, if you need one, is about 23 bucks so that's not painful. I'm not sure how hard it is to replace though. The only ground I have seen is the one in the battery box area on the exhaust side but I'm sure there are others.

If I knew your carb was clean I would say get on that kick starter and ride.

I have worked on a few LX50's now and I have yet to see one with two clamps on the airbox side of the carb. I tend to make sure there is a clamp at the carburetor end and let the airbox connection do without. I would like to know if one clamp is normal too.

I'm not getting anything except a click at the relay now. Before this it has varied between silence, super labored starter noise, and what seemed like normal starter noise, seemingly at random. Now it is consistent, just the clicking. The last time the starter made any noise there was also a smell coming from the starter area. The testing indicates the relay and switches are good.

I am going to try the kick starter just to test for spark.

I think it will he easier to replace the starter with the carb out, so I will clean it then. So much for isolating problems and tackling one by one!

It doesn't seem like that missing clamp is a big deal. It seems like it might run a little lean and the air wouldn't be filtered. I will put one on though. My only reference is the Scooter West videos and those show a clamp there.

How do you view the videos on this site? They all show up as unavailable to me. Even the one I posted.