Abstract: An oil burner includes a pivotal cover that exposes a unitary gun assembly. The gun assembly is movable longitudinally with respect to the central axis of the air tube of the burner by rotating a cam. A spinner assembly is positioned on the gun assembly. The air cone is divided into various surfaces, some of which are at angles to the axis of the air tube. The burner further includes an adjustable air entry port. A work station for facilitating nozzle replacement is also included. The firing rate is controlled by the air entry port setting, the nozzle used, and the position of the nozzle and spinner assembly in the air cone.