2003 Kawasaki Bayou 250 no power to ignition

[dkgg5755]

Im not getting 12v to ignition switch with key off or on I've jumped brown wire from starter relay to positive and neutral light comes on and push button start works. Can't figure out where to go from here any help appreciated l.

Edited August 12, 2025 by dkgg5755

[Gwbarm]

Sounds like it might be a starter circuit relay should be 2 small black boxes close to battery wiring in their own little rubber holder one is probably bad.

[dkgg5755]

I got it the white wire is broke somewhere in harness so instead of pulling everything off to get to full wiring harness im going to run a new wire and zip tie it out of the way

[Gwbarm]

Good work finding that, sometimes broke wires are hard to find.

[dkgg5755]

Thank goodness for a contious volt meter all I can say. Also the fact I have a kawasaki bayou 300 which is wired very similarly I've had for a few years and I remembered after a couple days checking wires the same thing happened on it as well my brain wasn't working correctly lol.

Next is tearing in for a top end rebuild I only have 70psi on compression tester.

[dkgg5755]

25 minutes ago, dkgg5755 said:

Thank goodness for a contious volt meter all I can say. Also the fact I have a kawasaki bayou 300 which is wired very similarly I've had for a few years and I remembered after a couple days checking wires the same thing happened on it as well my brain wasn't working correctly lol.

Next is tearing in for a top end rebuild I only have 70psi on compression tester.

My question is would it be easier to remove engine or just take apart on the frame ?

[Gwbarm]

Did you check with the manual to see what the compression is supposed to be with the decompression mechanism. Sometimes compression reads low because of the decompression mechanism.

[dkgg5755]

Yes

Already checked valve clearance as well they were within spec.

[dkgg5755]

I put a camera down spark plug hole could see a small amount of rust in there. So I'm  going to pull head and check those rings , piston and cylinder out.

[dkgg5755]

I just got finished checking the timing noticed it was about 2 teeth off and found that the outer camshaft bearing is worn out allowing the chain to be loose enough to jump timing. Do I need to replace inner and outer bearings while I have it apart ?

[Gwbarm]

Yes i would go ahead and replace both check the timing gear over good to see if it is in good shape. You also might want to replace the timing chain.

[Danno12]

Man, I found this site looking for info on a 2006 Bayou 300 4x4. I'm having the same issue with power at the ignition switch and you've had the same problem with 2 Bayous! I'm gonna check that out on Monday. 

 

This seems like a good place to get help and meet like minded peeps.

[bellarmine]

My Dad bought our Bayou 300 new in 1986, first model year, had it my whole life I'm just a bit older than it is lol.  There's a white wire coming from the positive battery post, and I believe goes directly to the ignition switch, that's the main electrical feed.  There should be an inline fuse close to the positive battery terminal, mine is about 4 inches down the wire.  It tends to blow occasionally due to overloads, winch etc, and you'll end up with a dead ATV no power anywhere.  I can check my schematic later if you wish.

[Danno12]

Yes, I would appreciate it! I confused 2 atvs I'm working on, this one is a 1986 as well. I do plan on starting at the ignition switch for power coming in and out and going from there. The switch did have high resistance

[bellarmine]

1 hour ago, Danno12 said:

Yes, I would appreciate it! I confused 2 atvs I'm working on, this one is a 1986 as well. I do plan on starting at the ignition switch for power coming in and out and going from there. The switch did have high resistance

No problem Dan, here is the wiring diagram from my OEM Kawasaki 1986 Bayou 300 shop manual.  Complicated looking isn't it?  See next post............

[bellarmine]

.............Here is the SAME diagram re-drawn and simplified by my late Dad, as a tribute to him (lost him in May....:o), we're both electrical engineers. 

It's a LOT simpler isn't it?  It's amazing, same parts same connections same logic.  Now that is a "Schematic".  The OEM one is a "Wiring Diagram" (pet beef)...:o)

As you can see, the power comes from the battery, thru a fuse and straight to the ignition switch.  There's a tap off the wire for the regulator sense, doesn't matter for diagnosis purposes.  So you should ALWAYS have power on one side of the ignition switch.  If not, bad fuse or bad wire.  Simply short the ignition switch out and the ATV should come alive.

We actually did that for a while with ours.  Our ignition switch kept opening and stalling the engine when we at high RPM trying to climb a hill, so for a while we just soldered a wire onto each solder nub on the bottom of the switch, and connected them together with fast-on terminals.  Instant hotwire.  We were too cheap to spend $50 on a switch, and never had a problem with theft.  After several years the switch magically 'cleaned' itself, so all fine now....:o)

Hope this helps, anything else let me know Dan.  Cheers!~ 

Bellarmine

 

Edited August 17, 2025 by bellarmine

[bellarmine]

P.S., Correction, the wire that taps off after the fuse, is actually the main battery charging feed wire from the alternator / regulator.  So if you run a new wire from the battery to the ignition switch, you will also have to connect that wire to the regulator, otherwise no charging...:o)

[Danno12]

I really appreciate the help! My condolences, but I imagine it was nice you and your dad are both electrical engineers. I think it would be nice to have that with my pops or son. Would make for some good conversations and problem solving together. 

[bellarmine]

You're welcome Danno, glad to help.  And thanks for the wishes.  You are right, we had a LOT of good problem-solving together, we both spoke the same language on everything, he taught me all I know in electrical and mechanical, standing me in good stead now.  Miss him every day but life moves on, so I'm moving on, one day at a time, best I can do..........:o)

Hope you find your power issue, as you can see it's not all that complicated, they just make it look so....:o)  Anything else drop me a line Danno.  Cheers!~  Bellarmine

[dkgg5755]

On 8/15/2025 at 12:25 PM, Gwbarm said:

Yes i would go ahead and replace both check the timing gear over good to see if it is in good shape. You also might want to replace the timing chain.

Seems timing chain and guides have been replaced think they ran it low on oil at least bottom end is still good. This is cam that came out of atv. 

[dkgg5755]

On 8/17/2025 at 6:47 PM, bellarmine said:

P.S., Correction, the wire that taps off after the fuse, is actually the main battery charging feed wire from the alternator / regulator.  So if you run a new wire from the battery to the ignition switch, you will also have to connect that wire to the regulator, otherwise no charging...:o)

I tapped into wire at regulator it is broke somewhere between it and ignition switch. Had power from battery to regulator same problem as the 300 I have. Didn't wanna have to to tear a wiring harness apart to replace one wire.