There is a issue with my ATV after not using it for 3 years there's a Leak coming from the petcock connection of the gas tank. When I push the start button and give the throttle a push the petcock starts leaking. What can be the issue?

 

Trying to start it kicks in the fuel pump and it's either leaking from a split fuel line or the petcock. Just check all the fuel lines.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse