2002 Yamaha Bear Tracker CDI Test

[pastorjeep]

Need a little help fixing a no spark issue. 2002 BT with the 2 wire ignition switch. I have 4 stators and 2 CDI's and 3 coils to test. The new stator reads 218 ohm, and .2 ohm, the one that came out of it reads 50K and .2, the other is 132 and .2. All of the coils are 0.00 ohm, and there is no way to test the CDI that I know. I have also confirmed the replacement stator pins match the factory locations. I did try to test milli-volts at the coil to see if it was getting any signal from the CDI but nope. IDEAS? 

Edited November 12, 2025 by pastorjeep

[Savage3]

OK sir, let's start at the beginning.  The coil, actually has 2 coils inside. Primary and secondary,  let's start with that. 

Keep in mind, resistance testing or static testing oftentimes produces inaccurate results. Ill post a video highlighting how to perform tests. 

 

[Savage3]

You also have a trigger coil that you can check air gap, some are permanently mounted and cannot be adjusted. You could also check the trigger coil for resistance.  Once again, dynamic testing is much more effective.

You would need a peak voltage adapter for your meter to produce accurate results during dynamic testing. The multimeter is not fast enough to capture cdi and pulse coil readings.

The resistance testing will let you know if the components have a ground fault or the ability to carry current. Worth checking out while you have it apart.

Go to manuals lib. and download a service manual to obtain accurate specifications. Otherwise, no sense performing the test. You need to know what the readings should be. Also, RM Stator has accurate you tube videos on how to perform all these tests. Rocky mountain atv does as well. 

Lets us know the results of your testing. Hope this helps Boss

[Savage3]

 

[Savage3]

https://www.manualslib.com/manual/826392/Yamaha-Yfm250xl-C.html?page=43#manual

[Savage3]

Example of coil testing results

[pastorjeep]

Thanks for the input. The pickup coil has a range of 197-231 in the manual and mine is at 218, my primary coil is at .2. So according to the manual they are both in spec. I also checked AC voltage and it was in spec for another page I read. I am getting nothing at the orange wire going to the coil primary. I put my fluke on AC milli volts and get nothing. So no signal from the CDI? I have an original CDI and a fleabay CDI. What are the chances both are bad?  

[Savage3]

Slim sir, I suspect you could have an issue with your safety circuit blocking spark. 

Example: the hand brake switch may not be working properly,  neutral switch, on/off switch etc. 

Look in your manual at starting circuit. Follow troubleshooting steps. Ensure all conditions are met and signal is making it to your components. Ie....the orange wire.

 

Meanwhile, I'll look for a wiring diagram and identify possible specific testing points that may resolve the problem. Post any diagrams or manuals you have that would be helpful.

Im not sure when they would be visible, but, worth a shot.

[Savage3]

Is the battery fully charged? No problem cranking?

What is the exact model number?

2002 BT? 250? Etc.....

[Savage3]

If ya can, put stator back on, crank it, post reading coming out of trigger coil. Should be low AC reading.

Please post results

[Savage3]

I found the diagram. Check the engine stop switch. That goes straight to cdi and could be the culprit of no signal coming out on orange wire from cdi.

The two wires coming out of switch should show continuity with switch in on position. No continuity in off position.

 

Between R/W and R/B

Edited November 16, 2025 by Savage3
Added information

[pastorjeep]

The stator is installed and it is producing about a 1/2 volt AC. The 1999-2001 Bear Tracker wiring is different from the 2002-2004 like mine. I will check the wiring on the switch. Thanks 

[Savage3]

Can we revisit the main coil again? Please watch video posted above and provide resistance readings on both primary and secondary. Get specs from your manual and compare sir.

Disconnect coil from circuit when testing Boss. 

 

The main coil that attaches to the spark plugs is comprised of 2 separate coils. A primary and secondary. Please make sure both meet specifications.

Thanks.

Edited November 17, 2025 by Savage3
Added information

[pastorjeep]

I have 3 coils (photo above) and tested all three. The primary on all 3 was 0.01 so I think my auto ranging fluke was ranging in the 200k setting. The secondary coil was between 6 and 9k on each of them. It looks like they are good. Thanks for the straight forward questions. It is helpful to go through the basics step by step. 

[Savage3]

No sir.......im referring to your ignition coil. The one that has a spark plug wire. It attaches to your spark plug.

 

This coil has two separate coils inside. Please see the video I've attached above. I need you to test this coil, both primary and secondary.  

[pastorjeep]

Yep, that is what I am talking about. Look in my picture and you will see 3 in the upper left corner. 

[Savage3]

 

[Savage3]

6 minutes ago, pastorjeep said:

Yep, that is what I am talking about. Look in my picture and you will see 3 in the upper left corner. 

OK sir, got it. Sorry, I misunderstood. Now can you get a reading while cranking on the hot wire that attaches to the coil?

Edited November 18, 2025 by Savage3
Punctuation

[pastorjeep]

Yes, I tried both regular AC volts, and AC milli-volts and get nothing. Also tried DC volts just for the fun of it but manual says AC.

[Savage3]

Unhook the wire from coil. Put black lead on good ground.  Red lead on wire that attaches to coil. Make sure it is in neutral, brake pulled. (in short, safety requirements met)

What is the voltage reading?

I believe yours is ac cdi and you should receive an ac pulse. Hopefully your meter can catch it without a peak voltage adapter. It may not be accurate, but, at least we will know you have signal and the cdi is working.

Edited November 18, 2025 by Savage3
Added information

[Savage3]

10 minutes ago, pastorjeep said:

Yes, I tried both regular AC volts, and AC milli-volts and get nothing. Also tried DC volts just for the fun of it but manual says AC.

So, you're not getting signal from cdi to coil. Possibilities: can you trace that wire back to where it attaches to cdi? See if you have signal at the pin on cdi. 

Test the wire itself at both ends, ensure you have continuity on the wire itself.

Your meter may simply not be fast enough to read signal without adapter.

[pastorjeep]

The orange wire has continuity and 1 ohm. I will test the signal on the CDI pin in the morning.  

[Savage3]

Don't forget to check that kill switch as well if you haven't already done so. 

Check to make sure the signal is getting from trigger coil to cdi as well. We know you had signal from trigger, but, is it making it to the cdi. If not, cdi will not send signal to ignition coil.

[Savage3]

You can also disconnect kill wire from cdi. If spark returns, then you have faulty kill switch or short in wire.

[Gwbarm]

You dont always show voltage when checking on a digital meter unless you have a peak voltage adapter. To check pickup coil and anti kickback coil i generally use an anologue meter the sweep hand is more sensative and the voltage spike is so fast if you blink you will miss it.

[jen]

I have a Simpson...LOL   Won't a spark tester light pick that up?...I have used a Timing light also.   That's an antique.

[Gwbarm]

I have never tied it but it is so instantaneous either not be very bright or not see it at all. Simpson with needle will pick it up. I just use a craftsman about the size of a deck of cards. All my good meters are digital been meaning to pick up a peak voltage adapter but so rarely need it havent spent the money.

[jen]

The voltage  bar graph along the bottom of My Fluke picks spikes.  Maybe not sure.  A timing light should.  You should get the Fluke scope...oscilloscope.   Fluke 199B...~$900

[Savage3]

The preferred method would be a scope. Dvom with peak voltage adapter works fine as well.

Resistor, diode, and led in series will also work. Main point is, we find out if the cdi has both input and output signal, hopefully,  eliminating that component as the problem. 

We are hoping for a poor ground or open circuit.

[pastorjeep]

I have not been able to look at it this last week. Hopefully I can do some more test that you guys suggested in a day or two. Thanks