Modern Vespa

Hello everyone
After sitting outside for 7 years without used in trying to restore my Vespa
So far I have replaced the cdi unit which gave me a spark
Replaced the fuel line and fuel tap which was blocked
And now I have encountered yet another problem as when I try to crank it then after like 10 attempts it starts but only for like 3 seconds before slowly turning off this has happened Like 5 times now and even when adding throttle it still just slowly turns off and can't idle
Could it be a clogged up carburator or low compression?
Thanks to everyone,Oliver

Try replacing the spark plug. An old plug that tests good can still be enough off to cause problems. It is a cheep fix and can be all the engine needs to run right.

OK, I see in your other post you already replaced it.

Carb needs to be cleaned very well. It will be full of varnish.