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Banshee's Electrical System: You've Got Questions, We've Got Answers

Mar 9, 2024

If you need a quick resource for the Banshee electrical system, you're in luck! Ben Boal, a Banshee rider, created a handy guide intended for other riders with the electrical systems of Banshees! Download a PDF of the full reference guide here (including advice on removal, troubleshooting, and electric system modifications).

While the specifics listed here are based on Banshee’s electrical system, the principles remain the same. They are similar to other simple 2-stroke motors (as always, a service manual will provide specific testing values and is a sound investment).

Here is the lowdown. On a relatively simple electrical system like a Banshee has, it’s all about generating electricity just to fire the spark plugs. When electricity is produced by the stator and flywheel, it has a positive charge and wants to find the easiest path to negative or ground-like water flowing down a river. Along the way, we can use the electricity to do stuff for us.

It's very important for the wiring and connectors to complete the path between the source of electricity (the stator) and, ultimately, the ground (the motor and frame) since the spark plug is connected to or “grounded” to the motor. This is the end of the electricity’s journey, making a fat spark between the electrical supply and the ground strap of the spark plug.

If the river were dammed, it wouldn’t flow, so it couldn’t turn the waterwheel. With an electrical system, the same is true if a wire is broken, the ground wire is loose, unattached, or not making a good connection to the frame. If the water or electricity’s path is unobstructed, like without a dam (water) or broken wire (electricity), it makes a “complete circuit.” If it does have an obstruction to flow, it makes an “open circuit” and cannot operate.

Another electrical term is “short circuit,” in which case the electricity had taken a path to the ground before we wanted it to as if the river was diverted away from the waterwheel before it got there, rendering it useless. While the CDI, coil, wiring, and switches can make a Banshee electrical system seem much more complex, each part of the system has a function and can easily be diagnosed when problems arise, as long as you know what each component should do.

Stock Electrical System Schematic and Specs

Now that we've supplied an overview, here’s an illustration of a typical Banshee stock electrical system; later year models will have additional wiring for brake lights:

Next, here are some electrical specifications for an ’87 and up Banshee:

Stator resistance:

Ignition coil should be 13.7-20.5 Ohms (red to green wire)
Pickup coil should be 94-140 Ohms (white/red to white/green wire)
Lighting coil should be 0.26-0.38 Ohms (black to yellow wire)

Coil resistance:

Primary coil should be 0.28-0.38 Ohms
Secondary coil should be 4,700-7,100 Ohms
Pickup coil gap: 0.015″-0.020″33f5
Spark plug: NGK BR8ES
Park plug gap: 0.7-0.8mm (0.028-0.032″)

1. Stock Stator, Pickup Plate, Pickup Coil 2. Stock Stator (after removing Flywheel) 3. Factory Coil 4. Adjustable and Stock Stator Plate 5. Flywheel 6. Degree Key

Banshee Electrical System Component FAQs

Here are some FAQs about Banshee's electrical system and components.

Why is a functional electrical system important?

A: At worst, it flat won’t run. Maybe worse, it’ll run like crap intermittently, often for no apparent reason or without any common symptoms. However, learning a few basics will help you solve an electrical problem quicker and save you alot of grief.
What are the parts of a Banshee electrical system?

A: The basic Banshee electrical system consists of a stator, stator plate, flywheel, woodruff key on the crankshaft where the flywheel mounts, pickup coil, CDI, coil, spark plug wires, spark plugs, voltage regulator, taillight, headlights, key switch, a handlebar-mounted light & kill switch, and a wiring harness. Most Banshees (as equipped from the factory) also have TORS (Throttle Override System), and later models (approximately 2003 and later) have brake light systems.
What is a stator?

A: A stator is at the heart of the electrical system, whose job it is to provide electricity to the rest of the electrical system. On a Banshee, the stator is found on the left-hand side of the bottom end of the motor, by removing the stator cover (black plastic on a stock motor) and flywheel. The stator itself is a doughnut-shaped device made up of several poles on the perimeter wrapped with copper wire, and has four wires going to the wiring harness.It is held onto the aluminum stator plate with three screws, and subsequently the stator plate is secured to the engine’s bottom end with three bolts.
How does the stator work?
A: The stator produces electricity by converting the kinetic energy of the rotating flywheel into electrical energy. In English, this means that as the motor spins, the flywheel connected to the crankshaft turns the flywheel around the stator and produces electricity. Similar to an alternator in a car (or a generator/magneto in other applications), the stator and spinning flywheel produce current for the ignition and lighting system. I should note that the ignition and lighting parts of the stator are separate, while both perform the same job of producing electricity, the ignition coil of the stator is a different part of the stator itself than the lighting coil.
What’s a stator plate?

A: The stator plate is a cast (stock) or machined (aftermarket) aluminum plate that the stator and pickup coil bolt onto, and is then bolted to the bottom end of the motor.
What does the stator plate do?

A: The stator plate holds the stator in place on the bottom end of the motor centered on the crankshaft so the flywheel can spin around the stator, and also has a mount for the pickup coil. Aftermarket stator plates either provide slotted mounting holes where the stator plate bolts to the motor, or have adjustable pickup coil mounts, allowing the ignition timing to be advanced or retarded.
What is a flywheel?

A: The flywheel spins around the stator to produce electricity, and also tells the CDI where the pistons are relative to TDC (top dead center). Also found on left-hand side of the bottom end of the motor, the flywheel fits over the stator. The flywheel is mounted to the tapered end of the crankshaft with a 19mm nut and lock washer, and is “indexed” to the crankshaft with a woodruff key (see Q#9). Located on the perimeter of the flywheel are two raised, rectangular tabs that the pickup coil uses to signal the CDI when to fire the spark plugs. The inside of the flywheel is magnetic, which in conjunction with the stator creates a magnetic field and then electricity.
How does the flywheel work?

A: Together with the stator, the spinning flywheel creates current for the ignition and lighting circuits. Together with the pickup coil, the flywheel tells the pickup coil where the pistons are so the CDI can fire the spark plugs. As the flywheel rotates, the pickup coil senses the location of the tabs on the outside of the flywheel, and sends a pulse to the CDI. Another function of the flywheel is to store inertial energy; by spinning on the crankshaft the flywheel’s weight can affect how fast engine RPM rises and falls. A relatively heavy stock flywheel will keep the crankshaft spinning longer than a lightened flywheel so when you let off the throttle and then hit it again there is less “lag” between the time that the motor hits it’s “power band” (or peak horsepower RPM) and the RPM that it was spinning when you let off the throttle. The downside of a heavy flywheel is that from a very low RPM it takes longer to hit the power band. Conversely, a lighter than stock flywheel has less rotating mass so the engine can accelerate quicker from low RPM to high RPM, but when you let off the throttle it will also decelerate quicker, which means getting back into the power band can take longer. Opinions vary, but in general you will see drag racers using lighter flywheels where every 10th of a second counts in quick acceleration, and woods racers using stock flywheels (or even adding flywheel weights in many dirt bike applications) to maintain RPM and minimize clutching, thereby reducing rider fatigue.
What is a woodruff key?

A: A woodruff key is a shaft key that’s shaped like a half-circle when viewed from the side. It is made to fit into a half-circle slot machined into a shaft, in this application the tapered end of the crankshaft. The inside of the flywheel has a rectangular slot or “keyway” that fits over the woodruff key as it sits in the crankshaft’s slot.
What does the woodruff key do?

A: The woodruff key sets the flywheel’s position onto the crankshaft. This is also known as “indexing” the flywheel to the crankshaft, or making sure that that the flywheel stays in the right position relative to the crankshaft. It’s important to note that the taper of the flywheel and the torque on the flywheel nut is what keeps the flywheel mounted securely to the crankshaft. The woodruff key itself does not bear any rotational or axial load, its only purpose is to index the flywheel to the crankshaft when the flywheel is mounted. That said, aftermarket offset woodruff keys (often called “degree keys”) are available that change the flywheel’s position relative to the crankshaft, thereby altering the ignition timing (see Q#54 & 55). A PROPERLY installed degree key is no less reliable than a stock woodruff key (you might need to rejet!), since its only function is to locate the flywheel on the crankshaft, so don’t be afraid of the thinner offset of the degree key, just make sure the offset is in the correct direction and the flywheel is installed correctly.
What is a pickup coil?

A: A pickup coil is a small black box mounted to the stator plate. It has two slotted mounts where two small Phillips-head screws secure it to the stator plate, and has two wires leading to the wiring harness. The side of the pickup coil facing the flywheel has a small round metal nub on it.
What does the pickup coil do?

A: The pickup coil senses the two rectangular tabs on the flywheel as it spins, and sends a pulse to the CDI. The CDI relies on this pulse to know where the pistons are at relative to TDC, and also at what RPM the motor is turning at by how many pulses it receives over a given time period. The pickup coil needs to be close enough to the flywheel tabs to sense them, but not so close that the tabs hit the pickup coil.
What’s a CDI?

A: The CDI, or Capacitor Discharge Ignition, is the “brains” of the ignition system. It takes the electricity produced by the stator’s ignition circuit, the input of the pickup coil, and tells the coil when to fire the spark plugs.The CDI is a rectangular black box located under the center of the rear fenders, just forward of the grab bar and seat latch. The CDI is mounted with a small flat rubberized metal bracket with two 12mm bolts, and has two short four-wire connectors (later models have a four-wire and a five-wire connector). There are no moving parts in the CDI, so it is a “solid-state” device, meaning that it is completely electronic.
How does the CDI work?

A: The CDI receives the electricity provided by the stator’s ignition circuit, and when it receives a signal from the pickup coil telling it the engine’s RPM and the piston’s location relative to TDC, the CDI then sends a current signal to the coil, which in turn fires the spark plugs. The electronics within the CDI will fire the spark plugs before (advanced timing) or after (retarded timing) the pistons reach TDC depending on engine RPM, to provide the most efficient spark and a clean combustion process. Banshee CDI’s have NO rev limiter, as some 2-strokes and most 4-stroke CDI’s have, that will cut out the ignition or otherwise prevent the motor from exceeding a preset RPM. The TORS system, which is independent of the CDI, performs a similar job by limiting spark if the emergency brake is “on” or the carburetor slides are open when the throttle is closed, but the CDI itself does not limit RPM. Don’t be fooled! The only rev limiter on a Banshee is the stock pipes, the CDI would happily turn 20k RPM, if your motor stayed together.
What is the coil?

A:The coil fires the spark plugs when it receives a current signal from the CDI. On a Banshee the coil is bolted to the frame just forward of the right cylinder, has two male spade terminals for an orange and black wire from the wiring harness, and has two spark plug wires with caps. It isn’t a slinky so don’t look for one on your Banshee.
How does the coil work?

A:The coil receives a current signal from the CDI, steps up the voltage, and fires both spark plugs at the same time. The fact that both plugs fire at the same time makes no difference on a 2-stroke motor like a Banshee, where the pistons are 180 degrees apart, and can be useful in locating potential problems with a single cylinder. Since one piston is on its compression stroke while the other is on its intake stroke, having both spark plugs fire at once is not harmful, and from a manufacturing viewpoint makes only a single coil necessary instead of independent coils for each cylinder. The coil works by using the electromagnetic field that is pumped into it on the primary winding side, and when power is taken away, the field “collapses” and the secondary winding(s) “collect” the power and jump it to the required voltage.
What are spark plug wires (or leads) and what do they do?

A: The plug wires are high-tension wires that carry a high voltage electrical signal from the coil to the spark plugs. They are mounted at the coil with a flimsy plastic retainer that tends to break easily if you screw with it. At the spark plug end they have a rubber spark plug boot with a built-in resistor, seen on the wire just before the spark plug cap.
What are spark plugs and what are they for?
A:The spark plugs thread into the top center of the cylinder head in a 14mm hole, have a white porcelain top half, a threaded silver metal bottom half with a small metal ground strap on the center pointing to a ceramic center electrode with a small metal tip. They receive the high voltage electrical signal from the coil and produce a spark (imagine that) to ignite the intake charge and initiate the combustion process. More than anyone ever wanted to hear about spark plugs, but they are a vital part of the ignition system.
What is a voltage regulator and what does it do?
A: The voltage regulator is a small, square, silver box with a single (usually blue) wire coming out of it leading to the wiring harness. It is mounted just to the right-hand side of the CDI under the rear fender, and typically one of the 12mm mounting bolts has an eyelet terminal with a black ground wire going to the wiring harness. The voltage regulator is NOT part of the ignition system, but part of the lighting system. Its purpose is to regulate voltage (you don’t say) to the lights, preventing them from blowing because of too much voltage. The voltage regulator on a Banshee limits voltage to 12 volts no matter what RPM the motor is at, since the higher the RPM the more voltage the stator will produce, the voltage regulator prevents the voltage at the light bulbs (and the wiring harness leading to the light bulbs) from exceeding 12 volts. As you’ve no doubt witnessed, at idle or low RPM, the stator’s ignition coil does not produce much voltage, as the lights are real dim. When you wind it out they light up pretty well, but if it wasn’t for the voltage regulator they would burn out quickly from the higher voltage.
What is the TORS?

A: TORS is the Throttle Override System found on stock Banshees. It consists of the large boxy carb tops, a switch on the thumb throttle housing, a switch on the parking brake perch, and a control box mounted to the frame rail above the left cylinder. The function of the TORS is to limit engine RPM if the parking brake is engaged, or if the throttle is released and the carb slides don’t. If the switch at the parking brake senses that the parking brake is engaged, it tells the carb tops not to lift the carb slides. Similarly, if the switch at the thumb throttle senses that the thumb throttle has been released, the carb tops won’t lift the carb slides. The problem with the system is that often the switch on the parking brake perch will fail to sense that the parking brake is not engaged, and will then limit RPM (the motor won’t rev past idle); adjusting the switch is the first solution, eliminating the TORS is a better one. Other drawbacks to the TORS is that the carb tops are huge and makes jetting more time consuming, the entire system is one more thing that can (and usually will) fail, and the system adds unnecessary weight. Eliminating the TORS is well worth the effort.
How do I eliminate the TORS?

A: Several companies sell TORS elimination kits (Toomey, Vito’s, etc.) that include aftermarket Mikuni carb tops, throttle cable, and an idle screw kit. The throttle cable and carb tops are a simple matter of removing the old and installing the new. The idle screw kit requires removing the carbs, drilling a hole (on the left side of the left carb and on the right side of the right carb), tapping the hole, filing the casting flat, and installing the screws. Drilling the hole is simple, just place a small piece of wood inside the carb to prevent the tip of the drill bit from dinging the opposite side of the carb when it goes through. Tapping the threads is also easily done, however be careful to use a good quality tapping fluid and run the tap in slowly; half turn in, quarter turn out, etc. Breaking the tap off is an exceedingly bad idea. Make sure to file off enough material at the end of the casting, about ¼”, so that the idle screw can raise the carb slide. Once installed, you can remove control box, the parking brake switch and thumb throttle switch (follow the wires to a connector and either disconnect it or cut the wires). Be sure to clean the carbs thoroughly and use compressed air to blow out any drill filings, and check the throttle cable free play.
OK I know the parts of the ignition system, but how does it work?
A: Basically, the crankshaft spins the flywheel around the stator, the stator then produces electricity and sends it through the wiring harness to the CDI, at the same time the pickup coil senses the tabs on the flywheel and sends a signal to the CDI. Depending on engine RPM, the CDI takes the electric current from the stator and the signal from the pickup coil, and sends an electrical pulse through the wiring harness to the coil, which steps up the voltage and fires both spark plugs. For the ignition system to work (and the bike to run), the flywheel has to be indexed to the crankshaft at the right position with a woodruff key and the flywheel nut torqued properly so the flywheel can’t spin on the crank, the stator needs to be intact (not shorted or broken circuit internally) to produce electricity, the pickup coil needs to be intact and positioned with the correct gap from the flywheel tabs, the stator plate needs to be mounted securely to the engine bottom end, the CDI and coil need to be intact, the wiring harness needs to be intact (not broken wires or shorting to the frame), all wiring harness connectors need to be connected and making a complete circuit on both sides (not loose so electricity can’t travel through), the spark plug wires need to be connected between the plugs and the coil, the spark plugs need to be gapped and operational (not fouled), and finally both the handlebar kill switch and the key switch need to be “on.”

Banshee Electrical System Testing FAQs

What do I need to test the Banshee electrical system?
A: An Ohmmeter, and some patience. A factory or Clymer manual is always a good source of information, and usually will have good illustrations, as well.
What’s an Ohmmeter?

A: An Ohmmeter is a small instrument used to test for “resistance” in an electrical circuit. Back to the water analogy from Q#23, resistance is a measure of how much water is flowing down the river, or if it’s flowing at all. In electrical terms, you can test resistance through a wire to make sure that it isn’t broken between two ends (this is important because even if a wire looks fine on the outside, the copper wire inside the plastic insulation can be broken in half), this type of test is called “continuity”. You can also use an Ohmmeter to test the stator and coil, in this case you would be looking for a certain resistance, or amount of Ohms, from the specs above to tell if the components are OK; if you tested it and found an abnormally high Ohm reading, it’s possible that the internal wiring of the device is broken (an “open circuit”); if you see a very low Ohm reading, it’s possible that it has a “short circuit” or the internal wiring is melted together where it shouldn’t be. Just remember that Ohms tell you how easily electricity can flow through a wire. Here’s a good link on how to use an Ohmmeter or multitester .
How do I use an Ohmmeter to test continuity?

A:To test for continuity, set the meter to “continuity check” if you have it, or “Ohms” if you do not. Some meters will have different test ranges, but for continuity you can just set it to 10-100 Ohms. Now simply touch one test lead (it doesn’t matter which one) to each end of the wire you want to test. If your meter beeps, listen for the tone; if you hear it then that wire has continuity through it. If your meter doesn’t beep, look at the meter reading; a very low Ohm reading (close to 1 or 0) means that you DO have continuity through the wire and it is OK; a very high reading (the needle pegs out on an analog meter or the digital meter reads “- -“, or infinite Ohms) means that the wire is broken somewhere and electricity cannot flow through it.
How do I use an Ohmmeter to test resistance?

A: To test resistance, set the meter to “Ohms”, if several ranges are available on your meter select the one closest to what you are looking for. For example, if you’re testing the ignition coil of the stator, set the meter to read 10-100 Ohms.Then touch one test lead to each of the terminals that the wire color you’re looking for is attached to (in the ignition coil example, put one test lead on the terminal for the red wire and the other test lead on the green wire’s terminal), then read the meter to tell how many Ohms of resistance are between the two test leads. When testing resistance, it DOESN’T matter which color test lead you put where, like continuity you are just testing how much, if any, electricity can flow through. In a Banshee application, there are no components (other than inside the CDI) that you can test that will matter which way electricity can flow. In the example, it doesn’t matter if you put the black test lead on the green wire or the red wire, or the red test lead on the green or red wire, the results will be the same. Again, be careful with the connector terminals and don’t test resistance with the motor running!
How do I test for spark?

A: One of the easiest and most common electrical system tests is to check for spark. You don’t need anything except a wrench to remove a spark plug to do this. Make sure both the key switch and the handlebar kill switch are “on”, and it would be a good idea to turn off the fuel. Remove one spark plug cap, and then remove that spark plug. Stick the spark plug back into the cap, and hold the end of the spark plug against the cylinder head (the very tip of the spark plug that is usually inside the motor has a small metal strap on one side, hold that “ground strap” against the top of the motor or one of the head nuts). Now watch the tip of the spark plug and kick the motor over. You should see a fat, blue spark at the end of the spark plug, that’s a pretty good indication that your ignition system is operational. If you don’t see a spark, try kicking it a couple more times, or try holding the ground strap against another metal part of the motor. It’s also easier to see the spark out of direct sunlight, so don’t panic, get it into a garage and it will be a lot easier to see.
How do I test the Ignition Coil on the Stator?

A: Using an ohmmeter and the specifications above, check the resistance between the red wire and the green wire on the four-wire harness coming out of the stator. Find the four-wire connector (usually white), at the front of the airbox on the right-hand side of the bike. Depress the little plastic retainer on the connector and disconnect the two connector halves. Take a look at the wire on the connector towards the front of the bike, it should run under the carbs and into the left-hand side of the motor’s bottom end. That is the connector you want to test. On the back side of the connector where the wires enter, locate the red and green wires. Set your ohmmeter to test resistance (and the correct range if you need to), and touch one test lead to the terminal on the red wire, and the other test lead on the terminal on the green wire. Your ohmmeter should read between 13.7 and 20.5 Ohms. So, if it reads 15 Ohms your stator ignition coil is OK, if it reads “- -“ or infinite Ohms or anything less than 13.7 or more than 20.5, then the stator is shot.
How do I test the Pickup Coil
A: Same as the above question, except you will be testing between the red & white wire and the green & white wire in the four-wire connector. You should have between 94 and 140 Ohms between these two wires. An important note is that the pickup coil needs to have the correct gap between it and the flywheel tabs. To check the gap, rotate the flywheel until one of the tabs on the outside lines up with the pickup coil (either by hand or by moving the kickstarter slowly). The gap should be between 0.015″ and 0.020″, if you need to adjust the gap loosen the two small Phillips-head screws where the pickup coil mounts and relocate it, then retighten the screws. If you’re in a real bind, you can use a matchbook cover to check the gap, it’s about the same thickness. Just like adjusting valves on a 4-stroke motor, the feeler gauge should slide easily into the gap with just the slightest drag, it should not be a bitch to cram the feeler gauge in there (that’s too tight!) and you shouldn’t be able to bounce the feeler gauge back and forth inside the gap (too loose!).
How do I test the Lighting Coil on the Stator?

A: Similar to the question above, check the resistance between the single yellow wire and the single black wire coming out of the stator. Usually right near the four-wire connector at the front of the airbox on the right-hand side of the bike, you will find the two single wires with hooded bullet-style connectors. Simply pull the connectors apart, and test between the yellow and black wire that leads to the stator. Your ohmmeter should read between 0.26 and 0.38 Ohms.
How do I test the coil and spark plug caps?

A: Locate the coil on the bike, it’s bolted to a frame rail just forward of the right cylinder. Unplug the orange and black wires from the wiring harness to the coil, and pull the spark plug boots off the spark plugs, then use a 12mm wrench to remove the coil mounting bolts. Many bike shops and dealerships have a bench tester for coils, if they’re nice they might just test it for free…in addition, resistance tests may test OK but the coil can still be bad, so if possible have it bench tested or swap in a known working coil to be 100% certain, even if you got to pay a little bit for it. To test the coil, use an ohmmeter to first measure the primary side resistance between the “+” and “-” terminals that connect to the wiring harness, you should have between 0.28 and 0.38 Ohms. Next test the secondary side resistance between the “-” terminal and the connector inside EACH spark plug boot, you should have between 4,700 and 7,100 Ohms in each one. If the secondary side test shows an open circuit (infinite resistance), remove the spark plug cap and test directly to the wire, if you then get the right resistance, replace the spark plug cap and test again; if it’s still infinite the cap is bad. If you still show an open circuit at the end of the spark plug wire, remove the wire at the coil and test again; if it is still infinite Ohms, the coil is shot, if not the spark plug wire probably is bad.
How do I test the handlebar kill switch?

A: Using an ohmmeter, test for continuity between the black ground wire and the white & black wire, when the switch is “off” there should be continuity between the two wires, when the switch is “on” there should be an open circuit. Find the connector for the handlebar kill switch and light switch, usually located around the bottom front of the fuel tank (you may need to remove the fuel tank to get to it). Depress the little plastic retainer on the connector and disconnect the two connector halves. Put the ohmmeter test leads on the black and white wires on the switch side of the wiring harness, with the switch set to “on” you should have infinite resistance or an open circuit (no electricity can flow). When you turn the switch “off” you should have continuity or a small amount of Ohms indicating that the circuit is complete (electricity can flow through).
How do I test the key switch?

A: Similar to the question above, EXCEPT the key switch works just the opposite; when the key is “on” there should be continuity between the black & white and the black & red wires on the switch side connector, and when “off” there should be no continuity. On the wiring harness side of the switch (don’t ask me why the wire colors are different or why there are four wires on the switch), the CDI needs to have the black & red wire grounded to the black wire to run, and when that circuit is opened it will shut off. See Q#60 on how to eliminate the key switch. As above, test the key switch by checking for continuity between the black & white and black & red wires, except when “on” there should be continuity and when “off” there should be no continuity.
How do I test the voltage regulator?

A: Check the blue wire connector and the black ground eyelet on the voltage regulator’s frame mounting bolt. If that’s OK, and your headlights explode when you hit high RPM, it’s probably shot. To test the voltage regulator, you’ll need to rig a tachometer, and test the DC voltage at one of the headlight connectors at two different RPM’s while the motor is running. Remove one headlight connector by depressing the little plastic retainer and disconnecting the connectors. Start the motor, turn the headlight switch on to “high” beam, and have someone hold the throttle keeping the motor at 2500 RPM. With your DVOM (an ohmmeter won’t cut it here, you need a meter that can test DC volts) set to test DC voltage, touch the red test lead to the yellow wire on the wiring harness side of the headlight connector, and the black lead to the black wire in the same connector; it should read 11.5 Volts (if the reading is lower, test the lighting coil). Now have your helper hold the throttle so the engine is turning 8000 RPM, with the meter test leads on the same terminals you should read 16.3 Volts, if it is above this reading the voltage regulator is toast. If both tests check out OK, repeat the whole test with the red meter test lead on the green wire, with the light switch set to “low” beam. You should get the same readings, if the voltage higher than specified, replace the voltage regulator.
How do I test the wiring harness?

A: Using an ohmmeter, check for continuity between connectors for each wire color. Simply unplug the connector at each end of the wiring harness that you want to test, and put one ohmmeter test lead on the terminal for the same color wire on both ends. For example, if you wanted to check the wiring harness between the stator and CDI, unplug the connectors for each, put one test lead on the red wire terminal at the stator, and the other test lead on the red wire terminal at the CDI. You should have continuity between the two, then move on to test the green wire, then red & white, then green & white. If you have continuity for each wire color, then you know the harness is intact. If you do not have continuity, first make sure the terminals are secured to the wires at the back of the connector, and that the terminals are clean (no rust or dirt inside the connector). If there are no other visible problems, chances are the wire that has no continuity has been severed inside it’s insulation somewhere and will need to be replaced. Here’s a pic of a stock wiring harness:
How do I test the CDI?

A: The short answer is, you can’t. Since the CDI is a solid-state electronic device potted (or encased) in silicone, about the only thing you can check on it is to make sure the connectors are tight and the wires are secured to the connector terminals. Short of buying an expensive replacement, the only way to test the CDI is to swap in a known working one. For this reason it’s usually best to test every other electrical component first, if everything else checks out then chances are the CDI is toast. If you’re lucky you can swap in a known working one from a buddy to make sure, but that’s not always an option. It should be noted that MOST CDI failures are simply working or not (go or no go), so if the bike will run occasionally and other times it won’t, the CDI may not be the problem, but if it flat will not run and everything else checks out OK, it probably is the CDI that is bad.

This article was written by Ben Boal, a Banshee rider who created this content to help other riders. Download a PDF of the full reference guide here (including advice on removal, troubleshooting, and electric system modifications). Selling of this guide is prohibited. It is intended as a guide only, and the author does not accept any responsibility.