Vespa Ciao won't start

I just bought a 1977 Vespa Ciao about 2 weeks ago. When I bought it, it would start but only run for a couple minutes before dying. I traced this to a clogged fuel line. The fuel would drip into and fill up the reservoir on the carb and the engine would run well until this fuel was used up. However after fixing the fuel line, the scooter will not even start. It will barely turn over with the choke on, but dies within a few seconds. I have checked the spark plug, cleaned out the carb, air filter, and fuel line. Everything looks to be working properly and it is getting a good spark, but still will not start.

I have not checked compression, but I assumed that it must be ok since the engine was running well before.

Any help?

Re: Vespa Ciao won't start

Bruce Wilkinson /

Maybe the petcock screen inside the tank is cl;ogged with dirt and rust. Drain the gas tank and remove the petcock and clean it. Flush the tank with the gas and catch it in a container through a coffee filter. Flush again and again with the same gas till it's clean. You should take the carb off and clean it again. It only takes one little piece of dirt to block the flow of fuel.bruce

Re: Vespa Ciao won't start

Don Pflueger /

remove the airbox and filter. spray some carb cleaner into the carb throat. close the choke. try to start the engine.

if it fires, you have a fuel problem. start at the gas cap and clean the vent. next, make sure the tank is clean and the gas is fresh and mixed to the correct ratio (if applicable). make sure the filters and valve are clean in the petcock. check the fuel lines for any kinks or blockage. remove and thoroughly clean the carb, useing a piece of wire and carb cleaner. run the wire thru every hole that you can find in the carb body and all its parts. follow up with blasts of carb cleaner.finally, make sure the reed valve is clean, and tight (if your bike has a reed valve).

if it does not fire, then you have either an electrical, or a compression problem. remove the spark plug. insert the spark plug into the spark plug boot. hold the base of the plug against the engine block. turn the engine over as if you were starting it up.

if no spark is present, try a new unused spark plug.

if no spark is present with the new plug, then check the simple things first. alot of bikes must have a good brake and tail light bulb in order to get spark. test the bulbs condition. if bad, replace with a new bulb. if good, then check the magneto. points are a very common item to fail. and most times its because they are dirty, or out of adjustment. clean them with an emory board or a point file. NEVER USE CARB CLEANER! blow them out good with compressed air. an average gap to set the points to is .014"-.018". you can find your actual timing and gap settings for your particular engine in service manuals located at in the moped repair section. coils rarely ever go bad. but, if the magneto is full of rust, every thing needs to be taken apart and cleaned. surface rust on the pick ups for the charging coils, and on the magnets can and will affect spark. make sure the wire from the ignition (ht coil) coil to the spark plug is in good shape. check the spark plug boot for continuity, especially if it is aresistor type boot. and if it is a resistor type boot, do not use a resistor type spark plug. lastly, check all wire connections to ensure they are clean and tight. on puchs, make sure the horn is hooked up.

if it has spark, then you have acompression issue. all 2 strokes must have at least 120 lbs of compression to run. so use a guage to test the compression. if less than 120 lbs, you must find where it is going. the usual places are, rings, head gasket, cylinder base gasket, intake manifold (where it mounts to the cylinder), or crankseals. a leak down test can be performed by any reputable lawn mower, auto, or motorcycle repair shop to tell you exactly where your compression leak is and how bad it is. replace or repair the bad parts.

if compression is higher than 120 lbs, pull the exhaust system off and make sure the port and the pipe are clean. these two things will prevent starting.



Dons Ride-Ons

used bikes

1695 Sunview dr

Lyndhurst, Ohio 44124

Re: Vespa Ciao won't start

I seriously don't know about this, but I was told by someone the reason mine did that same thing was because the engine seals were leaking. I don't know if the crank seals are the same thing or not. I actually never ran it myself, just the guy knew the previous owner. This prob'ly didn't help at all. Sorry.

Re: Vespa Ciao won't start

Don Pflueger /

bad crank sealswill prevent a 2 stroke from starting. follow the list i posted to you in my last post.

Re: Vespa Ciao won't start

Turns out, the little brass tube on the petcock was ruptured down the middle. The strange thing about that is, is that the fuel flow into the carb was good and the scooter used to start. It does not start now. It would actually run really strong for a few minutes an then die before. Because of this, I have a hard time believing it is compression.

I have just replaired the petcock and will try that out today. However the whole situation seems rather confusing to me.

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