How to trouble shoot your KX500 electrical system.

A closer look at your electrical system
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Sandblaster
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How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Sat Nov 03, 2012 6:50 pm

Spark issues are among some of the most common problems we hear on KX500's.
The older they get, the more problems we hear about.
Fortunately, the KX500 is one of the easiest to trouble shoot.
What should you check first?
This question will get you a lot of answers.
I say, check the cheapest and simplest things first.
Do you have a shop manual for your dirt bike?
If not, get one.
A shop manual will not only have the specs for your electrical system, it will also take you step by step on simple repairs to complete rebuilds.
Working on your Electrical system can be dangerous if you don't take the proper precautions.
I caught a bike on fire once because the spark plug lit off some fuel that had spilled earlier in the day, so..... Be careful!!!
Drain the fuel if required, empty the carb, remove the tank, what ever it takes to make it safe.
First, here is a picture of the KX500 Electrical system:

Image

As you can see, I included the wiring codes.
This system came off a 1994 KX500 but this system was unchanged from 1990-2004 and some parts are used as far back as 1983 :-)
When checking electrical systems I always start with the simplest and cheapest things first.
So, the first thing I always check is the Spark Plug
Spark plugs can be a hot topic :lol:
I like to run NGK plugs.
The NGK manual has the following plugs for the following years:
1983-1984 KX500 REGULAR B9EG, V-TYPE (GOLD) B9EGV, IRIDIUM BR9EIX
1985-1997 KX500 REGULAR B8EG, V-TYPE (GOLD) B8EGV, IRIDIUM BR8EIX
1998-2004 KX500 REGULAR BR8EG, V-TYPE (GOLD) N/A, IRIDIUM BR8EIX WITH A SOLID TERMINAL NUT
The spark plug gap for the 1983-2004 KX500 is .024" and the retail price is about 6.50 USD as of 10-27-12.

Image

Image

When in doubt simply replace the plug.
Just be sure to properly set the gap.
No, it will not come out of the box ready to go and using your eye to measure the gap simply isn't good enough.
Get a feeler gauge and set it.
As shown above, when using the feeler gauge the gauge should slip in with some resistance.
It should not be loose and sloppy.
***Important Information******Important Information******Important Information***
Many guys like to test their spark by removing the spark plug and kicking the bike over and watching to see if the spark plug sparks or not.
This method is fine.
However..... You must keep the ground electrode of the spark plug in contact with the engine at all times otherwise you can destroy your CDI and now you may have two problems to sort out and not just one.
Here is a picture of the ground electrode:

Image

The next thing I check is the Stop Switch sometimes called a Kill Switch.
Here is the book info:
Fits 83-95 KX500 P/N 27010-1161 approx. retail price 34.00 USD as of 10-27-12.
Fits 96-04 KX500 P/N 27010-1350 approx. retail price 34.00 USD as of 10-27-12.
However, the switches for both year ranges work exactly the same way so you can mix and match if you need to.

Image

You would be shocked how many times a 35 dollar switch kept a bike worth a few thousand from running.
You can test the switch with your ohm meter.
If you don't have one you can pick up a ohm meter from Radio Shack starting at about 25 dollars.
NOTE: Not all OHM meters have the same internal impedance values.
Just a quick note on impedance, impedance measures how easily a circuit conducts current when a voltage runs through it.
You measure impedance in ohms.
What this measurement tells you is how much of the voltage put into one end will make it to the other end.
The higher the resistance value is, the less voltage is making it through the circuit and usually meaning that something is getting hot :geek:
Your manual may or may not have those values recorded.
If the manual does not say what the impedance value should be they typically tell you what the part number for the correct OHM meter is.
Keep in mind that the impedance values will not make any difference for checking continuity, however, it will make a difference for checking resistance values.
Confused? Yeah, me too :D
Continuity is simply checking for any breaks in the wires.
Most OHM meters provide a Continuity setting.
In this picture I have my OHM meter set to check continuity.
Like a lot of other OHM meters my meter actually beeps when it is set to check continuity.
Some meters will light up or give you some indication that you have a good wire.
If you are not sure on your meter, set it to check continuity and touch the black and red leads together.
If it beeps or light's up then your good to go.
If nothing happens, read the manual that came with your meter.
You may have it set incorrectly or your battery may be bad.

Image

To check continuity of the Engine Stop Switch, set the ohm meter to check continuity and hold one lead to one wire and one lead to the other wire.
Have a friend push the button or get creative :D
You can use some alligator clips to hold everything together for you.

Image

If your ohm meter beeps when you push the button down then the switch is good.
If nothing happens when you push the button down and you know that you meter is good, then it's time for a new switch or disassembly, cleaning and re-testing of the switch.
You do not want to ride any motorcycle without a good stop switch!
If you don't have a ohm meter you can disconnect the kill switch and kick the bike over.
Some caution is in order because with the the kill switch disconnected you will not be able to easily stop your engine if it starts and decides to rev up to 25,000 RPM :shock:
If the bike suddenly starts you can either quickly reconnect the kill switch or pull the spark plug wire off.
Once the kill switch is disconnected, kick the bike over again.
Still no spark?
The next thing I check is the Coil.
Your coil should be embossed with F6T536
It FITS 83-04 KX500 P/N 21121-1186 and the retail cost is about 75 USD as of 10-27-12.
Before you do anything, look for cracks in the plastic case, frayed, broken, or melted wires.
Whether or not everything appears good, follow the steps outlined below.

Image

Did you just rebuild your bike?
Was everything working fine before you took it apart?
Did you paint your frame?
If you painted your frame, did you make sure that the Coil mounting area is bare of paint?
If you painted over the mounting area, your coil is not grounding.
Take a look at the picture below.
The frame is bare of paint allowing the Coil to make good contact with the frame and thus being correctly grounded.

Image

If your coil is properly grounded then your next step is to check the OHM readings with your OHM meter.
If you don't have an OHM meter, you will need one for all of the next processes.
A quick note on Electrical testing of resistance with OHMS.
If a part tests slightly out of spec, consider looking for other problems before going down to the Kawasaki dealer and ordering parts.
Generally speaking Electrical parts can't be returned.
Once you buy them, you own them.
There are many factors that can cause a part to test out of spec.
We talked about the internal resistance of the meter.
However, temperature and how the part was used can also affect your readings.
You should check resistance with the ambient temperature at approximately 70 degrees.
Of course your personal abilities can also play a role in your readings.
Before ordering a part, check all the other components first.
Then, if you think you have narrowed down the problem, take the part to your local Kawasaki dealer and have them test it BEFORE you buy anything.
Most dealers will test the parts without charge but it is always good to ask them first.
Below is a picture of the coil with the various parts labeled.

Image

To test the coil, disconnect the primary wire and the spark plug wire (Secondary wire).
Set your OHM meter to test OHMS.
More expensive OHM meters will have an auto range feature that will automatically select the correct range for you.
My cheapo unit does not have auto range so I have to set it for the range desired.
In this case the reading for the Primary lead (Orange Wire) should be 0.26-0.36 ohms so I had to set my meter to 200.
Setting the meter to 200 means that it will test from 0-200 OHMS.
Hook up your OHM meter with one lead to the orange wire and the second wire to ground on the frame.

Image

If your readings are a little different then 0.26-0.36 ohms don't worry about it yet.
I have 3 coils for a KX500 that all work perfectly and yet every one of them reads between .4 and .5 OHMS.
As long as it is close that is good enough for now.
If you get no reading at all, take your coil to your nearest Kawasaki dealer and have them test it.

Now we are going to test the secondary.
If you don't have the auto range feature, set your OHM meter to the range as required.
I had to set my OHM meter to 20K.
Take the OHM meter leads and touch one to the Secondary lead (Spark plug cap) and the other lead to ground on the frame.
The reading for the Secondary lead (Black spark plug Wire) should be 2.6K -3.6K ohms.

Image

No reading at all?
Disconnect the Spark plug cap from the Secondary wire as shown below.

Image

While leaving the coil bolted to the frame test again.
All 3 of my coils came up 3.0-3.1K so they are all good (Which I already knew :-)
If you still get no reading, take your coil to your nearest Kawasaki dealer and have them test it.
As a final note on Coils, some people mistakenly believe that you can set your OHMS meter to do a continuity check for the primary and secondary wires. If it beeps that is good enough.
Not true.
Your OHM meter may or may not beep and the coil can still be good or bad.
Use the steps above as these are the most accurate way I know of testing.
Stator

Image

To check the stator, leave the stator attached to the bike so that it will be properly grounded.
Next, disconnect the Stator from the other wires.
Here is the OHMS specs for 89-04 KX500.
Black/White to Black/Yellow 153-230 (Ricky Stator says you can run it up to 350 with no issues. I have also ran them out of spec with no issues as well) Since I don't have an Auto Range finder I had to set my switch to 2K. My Stator read 290 but works fine.
White/Red to Black/Yellow 7.9-11.9 Since I don't have an Auto Range finder I had to set my switch to 200. My Stator read 11.0. Good!
If yours is a little out of spec, don't get upset yet.
Finish testing all the other components first....

I HAVE UPDATED SPECS FOR ALL YEARS OF KX500 STATORS BELOW

Fly Wheel

F4T107 71 FITS 92-04 KX500 - 21007-1241 Retail price 324.00 USD as of 10-31-12
F4T102 71 FITS 89-91 KX500 - 21007-1183 Retail price 357.00 USD as of 10-31-12

Image

Image

To inspect the fly wheel you will need to remove it.
To see what all is involved in removing your Fly Wheel, I have an article on how to remove one from a RM250.
The process is exactly the same.
You can check it out here:
viewtopic.php?f=40&t=118

There are two main area's of concern that I will cover.
1. The flywheel can't have any dents in it..
If your eye's are not the best, put on your reading glasses or get a magnifying glass out.
Both if required :geek:
Look very carefully for any dents inside or outside.
Most likely dents will be inside if at all.
If there are any dents inside it most likely means that there was a problem at one time and something let loose.
If there are dents it can mean that the magnets are cracked.

2. The key way must be in good condition.
Look at the picture below.
See that Key way?

Image

Take the Wood-ruff key and put it into the Key way.
Here is a picture of the key:

Image

If there is any side to side play you will need to determine where the problem lies.
It will either be the key or the Key way on the fly wheel.
If the key is sheared you'll probably figure that out as you are removing the fly wheel as it can make getting the fly wheel off very difficult.
If both appear to be good, check the key way on the Crank shaft.

Image

Once again, take the key and put it into the key way on the crank shaft.
If it rocks side to side you will need to replace either the key, the crank, or both.
Another test of the flywheel, key and crank, is too loosely assemble the fly wheel on the crank with the key and try to spin it back and forth.
If it clunks, or wobbles around a bit, one of those 3 items or all may need to be replaced.
One last thing on these items to look for it how well the fly wheel fits on the crank shaft.
The taper of the rotor must be tight with the taper of the crank shaft.
Again, take the fly wheel and put it on the crank shaft with the nut torqued.
Try to move the fly wheel around while holding the crank still.
If it rattles, clunks, or moves at all then you better carefully inspect the taper of both the fly wheel and crank shaft to determine where the problem is at.
Another thing to look at is as you are spinning the crank around, see if the flywheel runs true.
If it wobbles around, even if it fits tight on the crank shaft, you will need to re-inspect to see where the problem is.

CDI or Capacitor Discharge Ignition.
FITS 89-04 KX500 –
P/N 21119-1267 -
19 deg BTDC @ 6000 RPM
Retail Cost as of 10-29-12 320.00 USD.

Image

According to the Kawasaki Manual you can't test the CDI as it requires special equipment.
Here is a quote: "The I.C. Igniter can only be tested with special electrical equipment and improper testing may damage it. Refer all testing to a Kawasaki dealer".
Just for grins I took my OHM meter and tested every combination of wires and this is all I could come up with.
These numbers may or may not mean anything :o
White/Red (Red test lead) to Stator Black/White (Black test lead) measures 1.3 when the range is set to 200M.
White/Red (Red test lead) to Stop Switch Black/White (Black test lead) measures 1.3 when the range is set to 200M.
White/Red (Red test lead) to Stator Black/Yellow (Black test lead) measures 1.1 when the range is set to 200M.
Black/Yellow (Red test lead) to Stop switch Black/White (Black test lead) measures 1.1 when the range is set to 200M.
Black/Yellow (Red test lead) to Stator Black/White (Black test lead) measures 1.1 when the range is set to 200M.
Black (Red test lead) to Stop Switch Black/White (Black test lead) measures 1.3 when the range is set to 200M.
Black (Red test lead) to Stator Black/White (Black test lead) measures 1.3 when the range is set to 200M.
Stator Black/White to Kill Switch Black/White has continuity.
Those were the only readings I could get.
Most likely your local Kawasaki dealer won't be able to test the CDI for you but it's worth a shot.
Unfortunately, if everything else looks good your only option may be to simply replace it and see what happens :o
As a final note, a tech tip that people use on older bikes may apply here as well.
This is not in the book but it does make sense.
Running a ground wire from your stator backing plate to your coil will insure that the system is properly grounding.
Remember, your coil is grounding to the frame and your stator is grounding to your engine.
Sometimes over time the engine and the frame are no longer grounded to each other.
This same technique can apply to add on's such as Regulator/Rectifiers, lights and other accessories.

Do you have more tips that you would like to see added to this article?
Let me know and I'll be happy to add them.
Thanks!
SB
If bikes are for kids I'll never grow up.

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Sandblaster
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Re: How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Thu Feb 28, 2013 8:52 pm

Here is some added specs for the different years of KX500 Stators.

FITS 83-85 KX500 - 21003-1109 - 336-504 OHMS BLACK/RED TO BLACK YELLOW - 14.2-21.4 OHMS RED TO BLACK/YELLOW - 10.4-15.6 OHMS WHITE/RED TO BLACK/YELLOW

(2 coil style) FITS 86 KX500 - 21003-1141 - 432-648 OHMS BLACK/RED TO BLACK/YELLOW - 4.0-6.0 OHMS WHITE/GREEN TO WHITE/RED

(2 coil style) FITS 87-89 KX500 - 21003-1169 - 432-648 OHMS: BLACK/WHITE TO BLACK/YELLOW - 4.0-6.0 OHMS: WHITE/RED TO BLACK/YELLOW

FITS 90-91 KX500 - 153-230 OHMS: BLACK/WHITE TO BLACK/YELLOW - 7.9-11.9 OHMS: WHITE/RED TO BLACK/YELLOW

FITS 92-96 KX500 - 153-230 OHMS: BLACK/WHITE TO BLACK/YELLOW - 7.9-11.9 OHMS: WHITE/RED TO BLACK/YELLOW

FITS 97-04 KX500 - 153-230 OHMS: BLACK/WHITE TO BLACK/YELLOW - 7.9-11.9 OHMS: WHITE/RED TO BLACK/YELLOW
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Motorrad
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Joined: Mon Feb 11, 2013 7:48 pm

Re: How to trouble shoot your KX500 electrical system.

Post by Motorrad » Thu Feb 28, 2013 9:35 pm

the black part you listed as watch for cracks... is just a plastic cover piece..

and the first thing I always do... replace all those shitty bullet connectors with Marine grade Locking Spade connectors. (insurance for us long distance desert race types)
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Re: How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Thu Feb 28, 2013 11:58 pm

Thanks for pointing out to me how bad my eyes are :shock:
Thanks for the tip about the Marine grade Locking Spade connectors.
spade connector.jpg
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Re: How to trouble shoot your KX500 electrical system.

Post by Motorrad » Fri Mar 01, 2013 12:08 am

Also you show testing ohms through the plugs.. Most coils that I've tested that fail.. It's the connecter..Or plug end... Sometimes you need to test infront of the connector...

I use stainless connectors...
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Re: How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Fri Mar 01, 2013 12:14 am

Yeah, I test at the plugs and haven't had a problem doing so but your right, testing the wires would be better.
It would certainly eliminate the chance of a bad plug causing a problem.
Since you replace the plugs anyway why not...
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Re: How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Fri Mar 01, 2013 12:16 am

Looking for a pic of the connectors you use.
I assume they are Adhesive Lined Heat Shrink style?
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Motorrad
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Re: How to trouble shoot your KX500 electrical system.

Post by Motorrad » Fri Mar 01, 2013 2:36 am

I use these connectors... because I ended up with a few 100+ bags for free.
Image

I only replace connectors on bikes that dont require original accuracy (restoration) (norton triumph etc etc).. for example.. on my husqvarna resto's I go to great lenghts to track down wire, and connectors that MATCH the original ones... even though they are lesser quality than the marine spade['s


here is how I go about it if I do..

Tools items required.

Soldering Iron
Solder
Proper 3point Crimp tool (not a pair of plyers)
Shrink tubing
connectors


Step one.

Strip wire back to fresh CLEAN Copper

step 2.

solder the wire... This prevents the copper from corrosion in the futrue.. also helps with wires breaking away from connectors... etc etc..

step 3.

put on shrink tube


step 4

crimp on connector


step 5..

shrink the shrink tube...
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Re: How to trouble shoot your KX500 electrical system.

Post by Motorrad » Fri Mar 01, 2013 3:53 am

Sandblaster wrote:Spark issues are among some of the most common problems we hear on KX500's.
***Important Information******Important Information******Important Information***
Many guys like to test their spark by removing the spark plug and kicking the bike over and watching to see if the spark plug sparks or not.
This method is fine.
However..... You must keep the ground electrode of the spark plug in contact with the engine at all times otherwise you can destroy your CDI and now you may have two problems to sort out and not just one.
Here is a picture of the ground electrodeSB

also have to watch this one.

This method got started back in the days of Points, and magnetos... when a nice orange orange' blue spark was easy to see...


in the era of CDI (a good functioning CDI) they will actually throw a white spark (higer voltage)... that is VERY hard to see in any kind of ambient light.

what looks like a NO spark situation to the naked Eye.. is actually a perfectly functioning spark..
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Re: How to trouble shoot your KX500 electrical system.

Post by Sandblaster » Fri Mar 01, 2013 4:59 am

Thanks Motorrad for your comments.
I know that many will benefit from his insights including myself.
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