The Ryobi 3100 PSI (2.5 GPM) Gas Pressure Washer is a powerful residential and commercial-duty unit powered by a premium Honda GCV190 (187cc) engine. It is rated for heavy-duty exterior cleaning jobs like driveways, siding, and stripping decks. Has full tank of gas and may need oil change. RY80940B. Compact hand-truck frame with 12-inch flat-free wheels. Built-in detergent tank. Has "Idle Down" technology, which saves fuel and reduces noise by idling the engine when you aren't pulling the trigger. The motor starts and funs fine but the pump fails to build pressure, possibly due to trapped air in the pump or a clogged nozzle, a stuck unloader valve or a damaged internal thermal relief/check valve.