Modern Vespa

Need some help. Scoot started cutting out every now and then, but now won't restart at all once it cuts out for a few hours.
Symptoms:
1 - When on stand/parked... I start it and 30 seconds later it idles super high and rear wheel goes crazy fast
2 - I can start it now and then and ride it maybe 100ft and it cuts out and I cannot start it again. I have to push it home.
3 - terrible on gas and smells like gas
4 - gas leak/wet hoses coming from gas tap/petcock. I tightened hose clamps, but is still acting the same.
5 - I changed airfilter

I'm getting close to thinking it's a bad petcock. Any ideas?

I would replace the petcock and if the vacuum and fuel lines bit old change them as well.

I'm not familiar with the carb on these things, but I had very similar problems on a bike a few years back and the issue was a defective float. I'd check the float for damage or deterioration as well as the valve.

I'll check the float, thanks. I hope it's nothing major. It was running great all this time

I'd start here, as this is definitely not right. The petcock is vacuum operated, and should block fuel when the engine is not running. It sounds to me like yours has failed and is flooding your bike.

p.s. you posted in wiki section, so your post is probably not getting as much attention as it normally would. Maybe ask a moderator to move it to "general"?

Perfect, thank you so much. I will order the petcock and hoses.

OK just did the following and my GT200 is back up and running like a champ.
1. Air filter - it was not too bad, but time for a change
2. Spark plug - the old one was completely burnt out
3. Fuel filter and fuel lines - not in bad shape, but lines were leaky at the petcock
4. Fuel pump - looked pretty warn, worth a change

I am however going to clean out the carburetor, to see if it gets better idle and performance, buy at least it's going steady again. Thank you all for your help!!!

Great to hear! Well done!

Awesome - great news.