Fuel Pump Test 3
Connect a 8-10" hose and a pressure gauge to fuel pump outlet line. Hold gauge so it is about 16" above fuel pump. If equipped, pinch off fuel return line. Start engine and idle on fuel in carburetor. Fuel pressure should be 5.5-6.5 psi (.39-.46 kg/cm2 ). If pressure is too low, too high or varies greatly with RPM change, replace fuel pump.