Trouble Starting VESPA

Check for bad gas -- water in gas , it is likely you have left the choke on.

I can't get my Vespa started.

Engine would not start because of bad Air-Gas mixture
I want to thank you and those on this forum for the great tips. I had painted the Crank Case on my Vespa ET4 and cleaned out the air filter. In the process I reconnected a hose to the air filter that had been disconnected. Bad move. It must have brought gas into the air filter and thereby upset the air-gas balance and I could not start the my Vespa ET4 engine. fast forward.... my Vespa ET4 Engine did not start for days.
After reading online here I realize that a gas smell was coming from my air filter that I had cleaned....BINGO...it was drenched with gas from reconnecting that hose and I think the upset in the air-gas balance was insuring my engine would not start.
[u]Solution to my Engine not starting:[/u] 1) Remove plastic piece ( I think it is called a faring) to expose easy access to air filter cover and it's screws 2) Undo screws and take off air filter plastic cover 3) Remove foam filter and soak in mix of water and dish fliud to remove gasoline. Wring out foam filter. Dip in water mix again and wring out again. 4) Start your scooter normally. Squeezing brake level and pressing starter button. You may here a bit of a cough sound and scooter should start right up...Mine did..... Ah air...we all need it and so does our bike engine. 5) Bike ran for a while and then I shut it off. 6) Tried to restart bike to make sure this was not a one time thing...engine started and then stalled out.... what happened..... Guess way too Much Air now. 7) Put back Clean foam air filter and re-screwed air filter cover on. 8) Tried to start bike again and it started right up. Great stuff. 9) Moved accelerator and bike purred like a large cat....Beautiful. 10) Went for a drive on the bike to work out the kinks and everything ran smoothly. Done..... (Hope this helps)

Check your fuel flo your tank may have sediments in it...