A fuel system pressure tester for motorcycles adapted to be connected in-line with a fuel tank female fitting and a fuel line male fitting, has a fitting body, a first fitting for connection with the fuel tank fitting with an internal, normally closed valve, a second fitting for connection with the fuel line fitting, a pressure gauge, and a manually operated valve with a valve actuating element and a connection for a fuel hose. The fitting body has an internal passageway connecting the first fitting, the second fitting, the pressure gauge, and the manually operated valve. A method of testing a fuel system of the motorcycle involves connecting the pressure tester to the fuel tank by connecting the male tester fitting with the fuel tank female fitting, and connecting the female tester fitting with the fuel line male fitting, energizing the in-tank fuel sending unit, and reading pressure within the tester indicated by the pressure gauge.