Modern Vespa

Another little issue.
I have changed belt and roller yesterday and fixed a leak on the exhaust and replaced the exhaust gasket as the previous was completely disintegrated.
Went for a spin yesterday and everything was fine.
Today I tried to start it and it took ages. Once it went on, there was lots of white smoke and the idle was pretty high.
Did some research and apparently it is the Clutch Seal? Is it possible?
If so, where it is located?

A failed clutch seal will not cause bad starting or white smoke. We need more information. Did you do any other work on the bike? Was the "white smoke" just condensation & not actual smoke? It can be normal to get some smoke after starting if you have been "churning" the engine on the starter due to some flooding of petrol.