RE: New to Gas engine question
Hi,
No pressure is required as the carbys on petrol motors are pumpers. The "pig tail" (circle) in the vent line is to stop the fuel slopping out of the tank. You have to have a vent or the tank will implode as the pressure is reduced as the fuel is sucked through, the vent allows the pressure outside the tank to equal the inside pressure.
Cheers,
Colin