Modern Vespa

I am probably the longest Modern Vespa lunker ever, and here I am looking for help. I have been reading the forum for years thinking I might get a Vespa one day. I have been riding a 2004 Suzuki VStrom 650 since new and the last few years it seems to get taller and heavier every year and at 70 years old I keep telling myself I need to downsize from that thing. I was a mechanic for many years during my working days and always thought I would like to get a project bike to work on. I recently found a non-running 2009 Vespa GTS. Owner said it had been sitting for about 3 years, was not getting fuel due to a bad fuel pump. Bike looked in good shape otherwise. Only 1733 miles. I got the VIN number and called Vespa dealer and they said the recall had not been performed, bring it in and they will replace it. Easy fix. Bought the bike and took it to the dealer next day. Pump was replaced under the recall. When I picked the Vespa up the mechanic said it tried to start but did not, check the spark plug. Got it home hoping the plug cap wasnt seated all the way, something simple. Cap was tight. PO had put in a new correct Iridium spark plug. I cranked the engine and grounded the plug and got a white/blue hot spark. So that isn't it. Check fuel. Pulled the fuel injector and cranked the engine and it just kind of spurted gas. Thought that the PO had maybe tried to get it running with old gas that had been sitting in the tank and partially clogged the injector. Thought I might have to get it cleaned. Disconnected the fuel lines and noticed that the electrical connector was broken loose and it fell off as I was holding it. That answered that question - new injector. So I ordered a new injector, belt, spare key (only had brown) variator tool and couple o-rings. Got my parts, installed the new injector. I know it will run now. Nope. Pulled the injector and cranked engine. Perfect spray pattern. Rechecked the spark plug, made SURE the cap was seated. Engine cranks as long as you hold the start button down. New battery fully charged. Not a hint of combustion. I have got a strong spark, clean fuel, new injector. And it wont start. I am sure I have good compression at only 1700 miles. I can feel compression pulses in the exhaust, even got my finger in the spark plug hole and felt good compression. Thought possibly there was still some bad gas left in the fuel line after the tank was drained. Disconnected the fuel line at the injector and got a strong stream of pure gas. Maybe there is a restriction on the air intake. Pulled the air filter and all like new. All the lights on the instrument panel work, headlight works, brake light works. Red immobilizer light has steady flash. All I can think of left is ignition timing or valve adjustment and at only 1733 miles I feel that possibility is not very likely. I have a good spark, good fuel and good compression. How can it NOT run? I must be missing something but for the life of me can not think of what else to do. I know there are some sharp guys on here. What have I missed? Thanks for any help - Steve.

Check the fuses in the glovebox and under the pet carrier front wall.

Welcome to MV.

It's a little suspicious that the PO changed the plug at such low km.

Maybe the ignition coil. I fixed a briggs and straton mower engine. My ignition coil magnet was bad.

I had a similar problem with my 2015 GTS300, hard starting and often no starting at all. I checked everything, and eventually replaced the ECU. It seems the ECU was faulty and was flooding the engine, something to do with the throttle position sensor. Anyway that fixed it, and the scooter has behaved perfectly for the last year or more.

Replacing the ECU is easy, but the part is expensive, and different models have different ECUs. So ideally you need to borrow one from a same model scooter, program it with your brown key, and see if that fixes the problem. Yes I know, easier said than done. In the mean time, make sure the throttle is closing all the way up to the stop, and not held slightly open by the cable.

Good luck,
Mike

Yes, as said, this may be an ecu issue. But still could be sparks. You are ex-tech I appreciate that, but are you really getting a good spark under compression do you think? Remember, resistance increases under compression so you may have a nice looking spark outside the cylinder but that can go away under compression. So the coil my be suspect. Remember, the dealers said it 'tried' to start. That's what normally happens when the coil is not providing enough voltage.

Can you swap out the coil with anyone you know for a test?

Welcome in MV Steve, the others said almost everything ... there seems to be a component that overheats or an oxidized connection (it could be a connector). Seems complicated but it's a simple engine, it shouldn't be difficult to repair it.

Welcome to the world of non-lurkerdom! Take the Vespa plunge and don't look back.

The Vespa started!!! I didnt want to, but since I had the air cleaner cover off, I thought I might give the intake just a quick shot of carb cleaner. It still didnt start but did crank over a little faster so I twisted the throttle wide open - and it started! Held it at about 3000 rpm for a few minutes to let it warm up, afraid it would die if I let it idle. Let off the throttle and it idled perfectly. Turned it off and it still required full throttle to start for some reason. Think I will ride it around for a while to see if some miles will help with starting. It still has the original tires and belt so I am just riding around the neighborhood to get a feel for bike for now. Still need to change the coolant, have already done the brakes. Right now I am a happy man! Thank you to all who replied.

Welcome to non-lurker status. Keep us informed of your progress.

OK - that points to your idle bypass passage being partially blocked. See this article by Cheekythomas:
https://cheekythoma3.wixsite.com/itsme/idle

Thanks for that suggestion Jim. I will check into it. Seems that the scooter does idle fine once it starts. I am going to give it a good ride around the neighborhood tomorrow to see if running it some brings any improvement. Thanks

Hopefully you've got things sorted. If not, try inspecting the injector o-ring and where the electrical connector attaches to the body. It's common on the 250 for the engine to bump up into the pet carrier and cause this to crack.

I had trouble getting mine to start and idle because of this. The crack was barely visible but it was causing an intermittent connection. Replacing the injector solved it. I also added the bracket for the 300 that protects the connector.

I think that is exactly what happened to mine. When talking to the previous owner she said they took some nice rides together. I remember reading on here that if you ride two up and have the rear shocks on the #1 preload setting and hit a big bump, you can break the injector. In the process of getting the Vespa running I checked the preload and sure enough it was set on #1. I dont plan on carrying a passenger and am pretty light weight but I still changed preload to #2. I think I need to get that bracket too. Thanks for the reply.

Took the Vespa out for a ride today. Still only starts with the throttle hold wide open, and wanted to die when throttle released to idle. Let it warm up for a few minutes and finally would idle on its own. Rode around the neighborhood for about 10 miles and ran well except to would back fire thru the exhaust when coming to a stop. Got brave and took it out to the highway. Got up to 45 -55 mph for a couple miles, turned down a side road back to the house, and it died at the stop sign. Cranked and cranked but would not restart. Pushed it home a half mile. Very disappointed right now.

Try opening your gas cap. Your evap system may not be working and you might be creating a vacuum in the tank. This commonly happened to my 2009 GTV250. If you hear a "woosh" when you open the cap, that may be the problem. I could ride my bike for an hour, pull off the freeway and it would die at the first light. I'd dismount, quickly lift the seat, release (not take it gas cap off, requires less than a second) and it would stop. Many times, the engine would surge. It was just another symptom that stopped when I opened the gas cap.

Best
Miguel

I would reach out to SDG on here or ring ScooterWest and talk with their service department. SDG helped me out with my GTS with regards to an electrical issue, and Max at ScooterWest got me hooked up with their service department regarding my Malossi kit for my GTS. Both are members, extremely knowledgable and Piaggio/Vespa dealers and excellent contributors on the forum

Hopefully the previous owner didn't turn the "not an idle screw" when he was having fuel pump problems. Can you reach out to him and ask if he ever tried to adjust the idle?

That is a good idea. I will do that. Thanks

I will remember to do that next time if/when it happens again. I had not ridden for more than 3 or 4 miles, but wont hurt to check. Thanks

Max left Scooterwest more than a year ago, unfortunately. But friendly people still answer the phone!!

Best
Miguel

I know I still miss him.

I may have to do that. I hate to ask a favor from a business I have not done business with. Thanks

Max used to call me 'patricio'. I think that's a Spanish/Portuguese term for someone who shares the same name as you do.

In Spanish, at least in the Mexican dialect, those who share the same name call each other tocayo meaning "name twins" I think.
Miguel

In Spanish, at least in the Mexican dialect, those who share the same name call each other tocayo meaning "name twins" I think.
Miguel