What size Carburetor Do I Need - Thanks

[SpookHouse]

What size Carburetor Do I Need:

Looking for carburetor for my Motofino QT-6 scooter...
It is 50cc, 4 stroke, 2007 model

Do you know if they require a 19mm or 18mm ?

Also, anyone have a line on where I can get the one I need online?

Thanks!

[blueboy5000]

Standard sized carb is 19mm for 139qmb Gy6 .

Amazon.com or scrappydogscooters.com.