Abstract: An apparatus cleans the exhaust gases of a motorcycle by feeding secondary air to the exhaust path of the engine. The amount of secondary air fed is controlled in proportion to the speed of the motorcycle. The apparatus includes a control valve which is operated to be opened and closed in response to the opening and closing of the throttle valve of a carburetor of the engine.

Abstract: A control system for preventing over-pumping of wells using submersible pumps. When the pump lowers the level of the water in the well, the control automatically diverts some or all of the water pumped back into the well to assure that sufficient water is available in the well for pumping. In this way, pump cavitation is eliminated and water is pumped from the well either at a rate equal to the capacity of the pump or, if the flow of water into the well is less than the capacity of the pump, at a rate equal to the flow of water into the well.