UH-OH!!!! Ignition coil on YZ 450

22 replies to this topic
  • sledtrash

Posted April 19, 2011 - 07:05 PM


So I just did a WR wiring swap out plus the crank and a few other odds and ends and got it all put back together and now it won't start. I tried it last night that is. Well I remembered about a ground that I had put on my to do list before it got buried under hoses and wiring on top of the engine, so I dug it out hooked it up and still no go. I then started going through the trouble shooting list.... got to the test on the top of the cap/coil and it is supposed to have .08-.1 ohms I'm not sure if I'm checking it wrong or if it is bad but I only have .01 ohms. I have my multimeter on the ohms setting 20k which gives me two decimal places should be what I need but I also checked it on the other settings nothing that looks any better.

Any inspiration? Or am I stuck with buying a new one? And did I cause it to go out by not having enough grounds hooked up? Or could their be another problem in the wiring harness of the bike??

I looked at the manual's for both YZ and WR and their resistance on the coil is the same so are the coils the same unit even though their part number is different?

thanks guys.

  • grayracer513

Posted April 19, 2011 - 08:19 PM


Which CDI are you running?

  • sledtrash

Posted April 19, 2011 - 09:30 PM


Which CDI are you running?

07 Wr CDI

  • grayracer513

Posted April 20, 2011 - 06:03 AM


Does the coil produce any spark with this system?

  • sledtrash

Posted April 20, 2011 - 07:33 AM


Yes is has a little spark. But I can't get it to fire and the resistance is wrong. I'm using a full wr wiring system as I did the changeout with the crank and stator.

Every other electrical component checks out other than the regulator I haven't checked input and output voltage.

  • grayracer513

Posted April 20, 2011 - 08:38 AM


If the resistance is wrong, I'd try a new WR coil. The output signal to the coil from the WR CDI could be a different voltage, but I don't know.

  • sledtrash

Posted April 20, 2011 - 02:37 PM


If the resistance is wrong, I'd try a new WR coil. The output signal to the coil from the WR CDI could be a different voltage, but I don't know.

That's not good!! :thumbsup:.

Ok and my dealer said that the coil on the wr, YZ, and yzf are the same so must have sent too much power through it and burned it up. Thanks gray!! Hopefully this is the last screw up on my part during this specific project...:thumbsup:

  • sledtrash

Posted April 25, 2011 - 05:51 PM


Gray, So I checked my output on my lighting coil too and it's way out of spec's too, can these be rewound and fixed or do I need to buy a new one of those too?

  • grayracer513

Posted April 25, 2011 - 08:28 PM


Might be an idea to see if your VOM is calibrated right. If the stator need repair, have it rewound for higher output, or buy one from the aftermarket ready to use.

  • sledtrash

Posted April 26, 2011 - 03:20 PM


All stator questions are concerning a 07 WR 450 Stator
Sorry for being such a pain as I'm learning to understand these systems. I have a few more questions.

1. At the moment my lighting coil in my stator doesn't have an acceptable reading on a ohm meter I'm guessing that it is bad? Can you rewind these and fix them or do I need to buy a new one?

2. If I do the stator mod as specified in http://www.bajadesig... Stator Mod.pdf instructions this makes the yellow wire the ground wire correct??

So if that is the case: 3 which wiring diagram for rectifier's/ regulator's do I make my harness correspond with https://www.bajadesi...- Universal.pdf going off of this link? If I delete the ground within the stator (which the stator mod does if I'm correct) then I'd need to go with the upper one correct?. Make a ground from the regulator to the chassis and make a ground from the Battery to the chassis and same with the lights?

4: If that is the case is the polarity of how they are hooked to the regulator an issue where the wires coming out of the Baja Designs regulator are two yellows a black and a red. The black is ground and the red is output power out so on the yellow wires does it matter which of my wires off of the stator go to which? (on this one I'm assuming not)

5: if I wire up my wiring as shown in the https://www.bajadesi...- Universal.pdf upper diagram everything should be fine and dandy and I'll be ready to go? :thumbsup:

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  • grayracer513

Posted April 26, 2011 - 06:48 PM


The stator mod tells you what it does; it combines the two existing circuits in your stator into one single circuit. The rectifier needs to see both ends of the circuit in order to produce a DC output current, so one way or other, you need both sides of the circuit to connect to the rectifier at the two yellow leads.

You should now have a total of 4 wires exiting the stator assembly. One pair is the red and white pair that runs from the pickup, or trigger coil, and these must not be modified. The other pair are the yellow wire, and the white that runs to the original rectifier. These two wires are the two ends of your single AC generator circuit.

IMO, neither of these should be grounded. I'll explain: If you ground the yellow (or the white, it doesn't matter) wire from the stator coils, you have to wire the entire rest of the motorcycle as shown in the second diagram. What's wrong with that? It complicates everything too much. AC and DC currents cannot share a common conductor or they become mixed, and bad things happen. Notice that the AC side (from the stator) is the only place that gets grounded. The AC current then flows in a loop from stator to rectifier to ground, and back to the stator, reversing directions constantly as the polarity changes. All of the other DC stuff, the lights the battery, the CDI, everything DC, has to be wired in a loop and can no longer use the frame as a ground anywhere, because doing so will pump AC into the battery.

Now let's look at the top diagram. In this one, we run two wires up from the stator to the rectifier without allowing them to ground anywhere. Then, anything DC can be grounded to the frame in the conventional manner as long as the battery is, and it will all work just fine. Much simpler, if you ask me.

So, your questions in order:
  • If you have continuity without a short, you will probably be OK, but you can have Ricky Stator rewind it for higher output, too.
  • Maybe, it depends (see above)
  • Deleting the ground within the stator doesn't bear on which diagram you use, it's how you connect the stator to the rectifier (see above)
  • The two yellows are AC. Which ever way you hook it up it's right half the time (doesn't matter)
  • Yes, the top diagram is my recommendation.

  • sledtrash

Posted April 26, 2011 - 08:12 PM


Thanks again Gray.

  • 123BigcoopDawg576

Posted April 27, 2011 - 06:56 AM


you can have Ricky Stator rewind it for higher output

No one does a re-wind for the WR (not that it cant be done). Both Ricky Stator and Trail Tech sell an after market Stator good for 100 watts which is more than enough for 2 hids :thumbsup:

If you want more info on WR stators read this thread:

http://www.thumperta...light=07 stator

  • grayracer513

Posted April 27, 2011 - 08:08 AM


The ratings of the Trail Tech and RS stators are 100W of DC voltage, too. It's over 120w AC.

  • 123BigcoopDawg576

Posted April 27, 2011 - 09:50 AM


The ratings of the Trail Tech and RS stators are 100W of DC voltage, too. It's over 120w AC.

Correct. However, the stock WR stator with a floated ground is much less and is only good for a single HID

  • intensem1rider

Posted April 28, 2011 - 06:03 AM


That reading you go on the 20k ohm scale is .01k ohms. Move the decimal place 3 places to the right to get your actual reading of 10 ohms.

Don't use the 20k setting unless your trying to measure resistances higher than the setting lower than it.

  • sledtrash

Posted May 01, 2011 - 10:01 AM


Ok I ordered a ricky stator, stator it comes with the regulator. I have a ign coil on the way so hopefully I have everything right and I can get to riding this thing soon.

BTW they said that they could rewind it, but for the extra 25 bucks why not have a higher output??

Since the stator comes prewired with the regulator that takes out all of the guessing on my part :thumbsup: I'll just hook my lighting into it and away I go!!!

Thanks for the help.

  • sledtrash

Posted May 06, 2011 - 12:38 PM


Note: this is my 06 YZ 450 with the WR wiring and lighting conversion.

note to gray: I have ran the wiring as you suggested. I'm starting to get frustrated with this project. :thumbsup:

here is the list of my troubles and what I've done so far.

I couldn't get it to start so I pulled my coil off and it had spark, the light was lighting up and everything seemed good. stuck it back in and cranked it over a million times (it seemed like it) and still no luck. So I started testing things. I pulled the coil off and tested it like the manual show's it was way below the proper numbers. Setting it aside I checked out my stator per the manual's instructions and it was bad too. So now I have replaced both of those and I'm still not getting spark. I unhooked the kill switch, and I have tried the main ign switch both on, off, plugged in, and unplugged. Nothing. Not sure but I'm guessing that it is the CDI unit.

What are some other things that I should look at??

In the beginning even after my ign coil tested bad, I had a little spark. now I have nothing!!!

  • grayracer513

Posted May 06, 2011 - 01:52 PM


Is this the Baja Designs modified stator? Did you do the mod yourself?

If it's modified, then the resistance numbers are going to be way off.

Which CDI are you running?

  • sledtrash

Posted May 06, 2011 - 02:28 PM


No the stock stator, and it was unmodified. I took your advice and bought the Ricky stator model. And I'm running a 07 Wr 450 CDI.

New ricky stator WR 450 stator,
New ricky stator regulator,
New Yamaha IGN coil,
New spark plug,

I just put all of this new stuff on the bike, and now nothing works.

Besides the lights I was kicking it over and my roommate said he could see the light lighting up.

I have the baja designs battery, before this it's bee sitting for several years... I guess it could be bad. But I should be able to get the bike to start shouldn't I?

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