got it to turn over but...

alright i got a vespa piaggio or somthing close to that name hehe, its a 78 i think. anyway it has the mechanism that you hit the switch on the back and the button pops out like Brandon Edge said. Me and my brother got it to turn over pretty easily but it won't fire up. You pedal it with the gas, choke, switches, and compression release all on, drop the compression release and the engine kicks in but it won't idle at all, by the time the moment from the pedalling stops the engine dies, any help would be apreciated.

Re: got it to turn over but...

XBrandon EdgeX /

You need to choke the carb. The lever should be on the right side of the carb. Push it down and then push it forward a little bit to make it stay choked. Then if it runs, give it a little throttle to un-choke it.

Also, make sure your idle is adjusted right.

Take the right side cover off the swing arm, there should be a hole in the side near the carburator. There should be a brass screw sticking out of the carb. It's the idle speed adjustment. Turn that in to make it idle faster. The correct idle speed will make it run but not spin the back wheel when it's off the ground.

If that doesn't help, you may have a clogged idle circuit.

The fuel flow for idle flows on a different circuit (set of passages) from the main jet. If you look at the bottom of the carb with the bowl off, you should see one or two tiny passages into the body of the carb. Make sure those are clean.

Re: got it to turn over but...

I think Brandon is right, try the choke and make sure your carb is really clean. Also, when you clean the carb (like it says in freds guide, carb cleaner and compressed air) make sure you install an inline fuel filter. If you dont, its possible that your clean carb will just get clogged again as soon as gas goes back into it. On my ciaos, I set the idle by screwing the idle screw all the way in, then let it out 1 1/2 turns. Other things to make sure you do: make sure your airbox is on tight, and make sure the bolt on the top that secures the carb is tight. Use a new spark plug, fresh gas, and make sure your mixture is correct. All of these things contribute to a properly running machine. It sounds like you are real close, keep at it and good luck!


If you need to clean the carb ...

These pics might help. The carb has an Idle jet that is often missed. Go to this link at look at Vespa Carb Cleaning. You will see the idle jet in Pic # 10. This may need to be cleaned. DON"T drill it out, use a very small piece of wire (strand from control cable) and c\blow it out with compressed air.

Here is the link;

go to Vespa Carb Cleaning folder

Re: If you need to clean the carb ...

Zippy is right. The idle jet can be seen when looking into the venturi from the engine side. It is a small hole in the body of the carb just below and in front of the brass tube that comes from the main jet. If it is clogged, you may not even see it. A telltale symptom is if it will start with full throttle but will not run at idle.

Chris S

Re: Zippy's Carb pix


Those pictures are better than any manual I've seen, and the explanations are brief and to the point. It's a great resource.


Re: If you need to clean the carb ...

brian away /

Hey Zippy, that step-by-step on the Vespa carb is great. A lot of the parts look almost identical to the carbs on Sachs and Puch carbs, do Vespas use Bing carbs, too?

Thanks for linking those pictures

BrianZippy wrote:

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