A gas burner includes a burner body that defines a plurality of forced induction flame ports. An air outlet orifice is mounted to an injet body at an outlet of an air passage such that the air outlet orifice is oriented for directing a flow of air towards the plurality of forced induction flame ports. A gas outlet orifice is mounted to the injet body at an outlet of a gas passage such that the gas outlet orifice is oriented for directing a flow of gaseous fuel towards the plurality of forced induction flame ports. A pneumatically actuated gas valve is positioned within the injet body. The pneumatically actuated gas valve is configured to adjust from a closed configuration to an open configuration in response to the flow of air through the air passage.