All Kawasaki Ninja ZX-6R models built after 1996 rely on an electric fuel pump to transmit gasoline from the motorcycle's gas tank to the its carburettors or fuel injectors. A faulty fuel pump is a primary cause of starting issues and can cause the motorcycle to stall by starving the engine of fuel. A ZX-6R's fuel pump is almost undetectable during normal operation, making it difficult to identify potential problems before they appear. However, there are two relatively straightforward tests you can perform to verify the fuel pump's operation if you suspect that it may be faulty.
Remove the seats from your ZX-6R, using the ignition key. Charge the motorcycle's battery with an automatic battery charger, then disconnect the battery charger.
Unscrew the bolts at the front of the gas tank -- between the tank and the handlebars -- and the bolts on either side of the gas tank, with a 6mm Allen wrench. Loosen the pivot bolt's nut, which is located on the bottom of the tank near the motorcycle's front seat rails, using a 10mm combination wrench. Lift the front of the gas tank upward on its pivot bolt and prop it into place with a wooden dowel.
Reach under the gas tank and pull the fuel hose off the fuel pump's outlet, positioned directly beneath the gas tank. Push a short length of soft plastic tubing over the fuel pump's outlet, then attach a pressure gauge to the tubing. Attach another length of tubing to the free end of the pressure gauge, and place the other end of the tubing into a plastic measuring cup.
Set the kill switch on the right handlebar to the "Run" position and turn on the ignition switch. Watch the pressure gauge and listen for a 3-second-long, high-pitched hum, indicating that the fuel pump is operating. If the pressure gauge indicates a fuel pressure reading less than 43 psi for 2003 and newer fuel-injected ZX-6R models, or 1.2 psi on 2002 and earlier carburetted models, the fuel pump is defective and must be replaced. Turn the off the ignition switch.
Take note of the amount of gasoline discharged from the fuel pump into your measuring cup. The fuel pump should have filled the measuring cup with a minimum of 64.4gr of gasoline. If the discharge is less than 6435gr, the fuel pump is failing and will need to be replaced.
Drain any fuel remaining in the plastic tubing into your measuring cup, then pull the pressure gauge and the tubing off of the fuel pump's outlet. Reconnect the motorcycle's fuel hose to the fuel pump's outlet.
Lower the gas tank onto the motorcycle's frame and screw its mounting bolts into place with a 6mm Allen wrench. Tighten the gas tank's bolts to 32 foot-pounds with a torque wrench.
Reinstall the motorcycle's seats.
Remove the seats from your ZX-64 with the ignition key and charge the battery completely, using an automatic battery charger. Disconnect the battery charger before continuing.
Follow the fuel pump's wiring lead to its connector, positioned near the motorcycle's ECU control box between or along the side of the front seat rails. Do not disconnect the fuel pump from the motorcycle's wiring harness.
Set your multimeter to read a 25 Volt direct current (DC) scale. Push the tip of the multimeter's red positive (+) probe into the yellow-and-red lead at the back of the pump's connector. Push the black negative (-) lead into the black-and-white lead.
Set the motorcycle's kill switch to the "Run" position and turn on the ignition switch. Observe the multimeter for a sudden 12 volt reading, which should drop back to 0 volts after three seconds. If the voltage reading remains at 0 volts, replace the fuel pump relay. Replace the fuel pump itself if the pump refuses to operate with the right voltage reading.
Turn the ignition switch off and remove the multimeter's probes from the fuel pump's connector. Reinstall the seats onto the motorcycle.
Your ZX-6R's battery must be fully charged for the duration of these tests. A weak battery will not provide the proper current to accurately measure the fuel pump's operation.