Abstract: An adaptor for liquid dispensing of precisely controlled amounts through an outlet of a liquid filled syringe includes a valve shaft extended through an inlet of the syringe, along the syringe and seated against a valve seat assembly at the outlet of the syringe. The valve seat assembly and a cylindrical casing cooperatively mount the syringe to a housing assembly. A spring within the housing assembly biases the valve shaft to a normally closed position against the valve seat assembly. By pressurizing the liquid in the syringe, timer actuation of a solenoid within the housing assembly retracts the valve shaft away from the valve seat assembly to an open position to force the pressurized liquid through the outlet and out of the syringe.