Modern Vespa

I have a 2009 Piaggio Fly 150 with under 400 miles that will not start. It cranks but will not turn over. There is spark at the spark plug, gas is flowing to the carb and the battery is fully charged. I have replaced the carb, the fuel lines, the starter and the bendix and still nothing, it just cranks but never starts. It was driven occasionally but never started reliably. There are no dealers or service providers within a reasonable driving distance from me. Any guidance on what may be the problem would be greatly appreciated. Thank you very much.

"Replaced the carb" with....??

O.S.

I was told and it appeared to be a OEM NOS carb that was sealed in the original box with Piaggio/Vespa tape. It looked identical to the original and fit exactly as the old one did. Due to the age and nonuse I opted to just replace it hoping it would resolve the issue - it did not. Is there a carb difference or problem I may not be aware of? Later I learned perhaps the bendix was not engaging so I replaced it and the starter while there but this also did not resolve the issue. Very troubling and frustrating. What might you think? Any feedback would be much appreciated.

How old is the battery? Have you had it tested?

A battery may appear to be fully charged but not have enough juice to turn the engine over fast enough to start.

Thanks for the reply. The battery has been and remains connected to a Noco trickle charger that indicates a full charge. When the key is turned to on, all the lights go on and when the ignition button is pressed the starter cranks, but the engine fails to turn over. The battery is not the original and not very old either.

This bike has been sitting unused for a long time. It's likely that other items have cracked. In particular, the intake manifold.

Have you sprayed ether into the head, and tried starting it like that?

After attempting to start, pull the plug and see if it is wet or dry

There is a possibility that you have intermittent or low spark, due to faulty CDI

Have you checked the valve clearances?

Thanks very much for the reply. I'll do as suggested and report back. How do I spray ether into the head? Through the spark plug hole? Thanks again.

When you replaced the carb, did you replace all the lines and hoses?

You could have a minor crack somewhere affecting your ability to start it.

Also, be sure to disconnect the EVAP line; your canister might be the culprit as well. I had that exact issue with starting. Once the EVAP line was disconnected, the bike started right up.

Thank you. Ill check all the lines and hose clamps. Hopefully you are correct.

If I read this correctly - the starter is turning, but you say the engine is not turning over. I presume that was the basis of your attempt to replace the bendix. If this is true, then trying to address spark, valve clearance, operation of the carb, EVAP system, or spraying ether into the air intake are not going to remedy the problem.

Dooglas: Yes you are correct - the starter is turning but the engine fails to turn over and start. I thought perhaps the bendix was was not engaging so I replaced it. There is spark and when I disconnect the supply line from the carb gas does flow out. If gas is flowing then I assume its not a vacuum issue either. The EVAP system has been removed and I have a new fully charged battery as well. Still not starting.

Remove the inlet from the air filter to the carb. Stick your fingers in the carb to move up the CV slide. Spray a fair amount of instant start (ether) in the carb. If the engine is turning over and you don't get a pop, then it's a spark problem. If it runs for a few seconds and quits, it's a carb problem.

Sort of confusing. Normally cranks and turns over are the same thing. Cranking or turning over without starting can be a failure to fire, due to no fuel or no ignition.

I know this sounds stupid, but it happened to a friend of mine. He tore apart his scooter, and it turned out that he had the kill switch on.