Warning! Comply with safety precautions when handling or working with fuel; note that the fuel lines are pressurised.
Remove seat.
Connect a test pressure gauge, BMW # 16 1 500, between fuel feed line and tank outlet.
Start engine and allow to idle.
Fuel pressure: Specification: 3.5±0.2 bar (49.8±2.8 psi).
Note: If fuel pressure is lower or higher than specification, check the fuel pump, fuel filter, pressure regulator and lines.