Gen 1&2 Electrical troubleshooting wisdoms
Before proceeding with any troubleshooting steps, I highly suggest you disable or remove any fuel management systems (Power Commander, Bazzazz, etc.).
Problem: Bike will not start and takes multiple attempts.
Important Symptoms: The gauge will power off and the clock will reset. The bike starts successfully after the first failed attempt with no problems. The bike fails to start more often when it is hot.
Likely Fault: This is a current draw problem. Usual cause is resistance in the grounding wires.
First thing to check is if your battery bolts are properly secured.
Next look for burned grounding wires or corrosion under the frame grounding bolts. The bike has two primary grounds bolted to the frame underneath the fuel tank.
Science: If one of the grounds gets corroded, the bike will have starting issues. The bike has two grounding points, but it needs both to operate correctly. If one of the grounds fails, the bike will have high resistance to a high current draw on the negative side of the circuit.
Problem: Bike will hiccup and sputter during hard acceleration. It feels exactly like hitting the rev limiter.
Likely Fault: There is a fuel delivery issue. Suspect the fuel pump or pressure regulator.
First, if you have a PC3 or PC5, investigate these modules. A firmware update may solve this issue. If that doesn't work, unplug the Power Commander and remove it from the equation.
Next: Perform a pressure test of your fuel system. The fuel pressure regulator or pump may be faulty. The pump itself can be replaced, but not the regulator. If your pump is fine and the regulator has failed, you can solve the problem by replacing the entire assembly.
The unexpected: Make sure this problem isn't because of a kinked fuel hose or a clogged fuel filter.
Science: A fuel pressure tester is one of your best friends when trying to diagnose mystery performance problems. A cheap test gauge from Harbor Freight works fine. Pay attention to the fuel pressure when you twist the throttle. The fuel pressure needs to be at a steady 40 PSI. The fuel pressure can fluctuate, but not by much, say no more than 3 PSI for a healthy system. Any significant drop in pressure during throttle twist will cause the bike to hiccup during hard acceleration.
Problem: Bike will hiccup and sputter during light riding at low RPM.
Important Symptoms: The bike feels like it wants to cut off. The bike seems fine at higher RPM. You may have to hold the throttle open while at a stop light to keep the bike from cutting off.
Likely Fault: This sounds like an ignition issue.
First, if you have a PC3 or PC5, disconnect these module and remove them from the equation.
Next, rule out your fuel system with a pressure test.
Next, clean your spark plugs.
Finally, if the Power Commander, spark plugs and fuel system are OK, replace your ignition coils. If the problem persists, consider replacing your throttle assembly and having the fuel injectors professionally cleaned.
The unexpected: make sure this isn't a clogged air filter, or you have too much oil and rust on your spark plug threads, or you have the wrong spark plugs, or you didn't torque down your spark plugs properly, or this is a loose connection between the ignition coil and the spark plug because the ignition coil's boot wasn't pushed far enough into the spark plug hole.
Science: A malfunctioning ignition system can have good spark at one part of the RPM band and bad spark in another part of the RPM band. Please note you cannot accurately detect bad spark by just looking at it while grounding a spark plug on the engine case. Please note that a bad ignition coil can still give good resistance readings when tested with a standard multi-meter.
Problem: When you turn the ignition key to ON, the bike's lights come on briefly or dimly, and the bike will not start.
Important Symptoms: The headlights work, but are dim. The bike was fine just a few minutes ago. After waiting a few minutes, the bike will start again just fine. The battery is fully charged, but the bike acts like the battery has low power.
Likely Fault: There is a current draw problem, and it's probably on the positive side of the electrical system.
First check your battery, make sure it is healthy and the terminals are properly tightened down. You can take out the battery and have it stress tested at an auto parts store.
Next remove and clean your starter relay. The starter relay is the small box attached to the positive battery cable. It has all of the bike's current running through it, and it will always have corrosion issues, especially if you have oil leaks or you ride in the rain. Often a simple cleaning will fix the electrical resistance issues with the starter relay.
Finally make sure that you check the voltage while the bike is running. A healthy charging system produces 14.4 volts at 3,000 RPM. If you are getting proper voltage, replace the ignition relay. If the problem persists, replace the battery.
The unexpected: Make sure the wires going to the ignition switch and the solder connections to the switch itself are OK. Make sure the left primary connector under the fairings isn't corroded.
Science: The bike's dim headlights are the key here. If the resistance is on the negative side of the electrical circuit, the bike's tendency is to completely power off. If the resistance is on the positive side of the circuit, the bike will still function but with dim headlights. The bottlenecks for the positive side of the circuit are the positive battery terminal, ignition relay, the ignition switch, and the main left connector located under the fairings near the left turn signal.
Problem: The bike will not charge the battery.
Likely Fault: Ta-Da!! Time to fix the charging system, the most common electrical failure on pretty much any motorcycle.
First and most likely, the stator has gone bad. Check the voltage at the battery and make sure it is around 14 volts at 3,000 RPM.
Next, if you replace the stator, pay attention to how it failed. Usually you will see a burn mark on the stator itself, which is a normal failure. If the stator appears fine, and if you see the stator wires are burned near the connector plug, then your stator failure was caused by one of the diodes in the rectifier going bad, which forced too much current through two of the three stator wires.
Finally, if your voltage is fine, and you've replaced both the stator and rectifier, and you are still getting low battery issues, replace the battery.
The unexpected: You can have a bad rectifier and still get around 14 volts at the battery, so never completely trust it if you have mysterious charging problems. If you replace your stator and the new stator fails within a few months, consider replacing your rectifier.
Science: The charging circuit is a separate "dog leg" from the rest of the electrical circuit, meaning that it can malfunction or even be sliced out, and as long as the battery is charged and still attached, the bike will continue to run. This is important to note because if your bike is having power issues that cause it to cut off, but it is able to produce 14 volts, then replacing the stator and rectifier will likely not solve the problem. The most common way for a stator to fail is for one of its three coils to short out, but the other two coils work just fine. This is important to note because if your bike can produce 12 volts at idle but has trouble reaching 14 volts at 3,000 RPM, then you definitely have a failing stator.
Problem: You keep seeing an FI code stating there is a problem with the servo motor. You can see that the motor works, or you have installed an eliminator
Likely Failure: There is an overall electrical problem that is causing the servo to malfunction.
First, refer to earlier troubleshooting regarding current draw problems and charging issues.
Finally: If all seems fine, replace the servo motor or install a Hellrazor's servo eliminator.
Science: I'm guessing here, the likely reason is the bike is unable to generate enough current to properly power the servo motor or the Hellrazor mod.
Problem: You start the bike, and it chugs and wants to cut off.
Important Symptoms: You have to hold down the throttle to properly start the bike. The bike seems to run fine after it warms up. It seems to only do this when you first try to start the bike.
Likely Failure: Sounds like the bike is running with an off fuel / air mix.
First make sure to check your idle setting, sometimes it needs adjusting when the seasons change.
Second check your air filter, make sure it's not clogged.
Next check your fuel pressure.
Finally remove and clean your spark plugs. Remove the Power Commander if one is installed. If you have ruled out the idle setting, air filter, spark plugs, fuel pump, fuel pressure regulator, and power commander, then replace your ignition coils. If the problem persists, consider replacing your throttle body assembly and having the fuel injectors professionally cleaned.
The unexpected: You will have this problem if you remove the secondary throttle butterfly motor, as it acts as a choke during cold start. Removing the secondary butterflies is fine, just don't remove the motor.
Science: Kawasaki's ZX-10R motor does not appear to be sensitive to a lean fuel mixture, but it is definitely sensitive to a rich mixture. Detecting intake and exhaust leaks and lean issues, while important, will likely not solve your running issues.
:: Just a shade tree mechanic keeping a 75,000 mile beast alive.
Last edited by antaren; 07-07-2015 at 03:53 PM.
Reason: Organization, updating information, included some helpful explainations