Cuts out at full throttle 2006 Piaggio Liberty 200

fuel flow or blocked main jet
have the carby overhauled and check for full fuel flow

Something has to be fubar with the main jet circuit of carb. That explains why it starts and then shortly thereafter shuts down. Also explains why when you give it gas it cuts out cold.

U have ignition but NO engine will run without proper fuel flow.

Hello crosby, it still sounds like a fuel delivery problem or fuel mixture. Also a possibility is a restricted exhaust. Like carbon buildup that is creating too much back pressure. The carb being "blown out" is not going to properly clean it. The best way to clean all the jets and passages is to remove it & have it boiled or ultrasonic cleaned. The not being able to kill problem is a wiring problem. The spark is not being shut off, (voltage) Trouble shoot these areas and let me know what you find. I hope this helps.

Make sure the carb is thoroughly cleaned, all jets not just main. The half choke is compensating for the slow circuit jet. Check your air/fuel mixture. Also, check the air and fuel filter. If all checks out fine and you still encounter the problem, could be : bad gas, wrong spark plug heat range, or most likely the diaphragm for the top of the carb.

If it is backfiring on deacceleration you have a fuel mixture problem and need to "sync" the carbs.
Sync Pro carb tuner works well. This is a precise four channel vacuum indicator designed specifically for intake synchronization of engines with multiple carburetors or throttle bodies.
Also, if you have not done so, check your plug wires for defects and resistors, if your wires have them.
Good luck, hope this helps.

I have had the same problem with my stepsons zip 50 and have done all the usual checks. The solution is from a piaggio technition. Take off the air cleaner and housing, start the scooter and bring it to the point where the engine dies. At this point spray easy start or a gasoline spray direct down the carb intake. If the revs pick up, you have a lack of crank case compression and the most likely reason is worn oil seals on the crankshaft. It sounds odd but the worn seals cause all kinds of strange problems.
Thats 2 stokes for you. Hope it helps, good luck