Moto 4 250 quad

Hi everyone. I’m a newbie here,from the UK. I have recently acquired a Yamaha Moto 4 250 quad. It has been layed up for the last two years in a barn. The farmer that owned it,had it for around 15 years. I now have it and was hoping for some help.
I cant read the VIN number as its rusted over and is so faint,can only just make out two numbers.
Anyway,got it running today,after cleaning the carb,but when I turn it off,fuel flows into the air box.
I am hoping somebody can identify the carb from a picture so I can either buy a new carb or get a rebuild kit.
Any help would be greatly appreciated.