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Sunstar PTO problem - updated 8/18/13


huffy

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The front PTO on my Sunstar has quit working. When the switch is on, my tester shows that there's power down to where the wires exit the PTO. So, I think it's something wrong with the PTO itself rather than just a bad switch or bad connection. I pulled it apart last night.

Front PTO.JPG

I think that the problem is that there's something wrong with this piece

Front PTO 2.JPG

Is this something that I can take/send somewhere to have tested and/or rebuilt? It looks like the individual parts for this clutch aren't available anymore (at least not through Jack's), and to replace the whole assembly is about $450. So, it's either find another used on on eBay or get this one fixed.

57e058768213c_FrontPTO.JPG.11e3b5640a7c3a51a6ebafb32b5907a9.JPG

57e058773018a_FrontPTO2.JPG.e481c108d74fba5dc29482d0be1763c7.JPG

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For starters, you can measure the coil. Check to see if there is resistance. I believe (not certain though) you should see somewhere between 2 and 3 ohms of resistance across the coil. If you are reading significantly less resistance, you may have a short in the coil. If you get no measurement, you have an open coil. Hope this helps get you started.

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What kind of gadget do I need to buy to test that? Just a multi-meter or something?

This electrical stuff is a sorcery that I have never understood. :D

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Set it back together on the floor and run a wire to the battery each side and see if it locks up, if it dose you should be able to pick it all up with the pully. That mean it works and you have other problems.

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There are also adjustments on the clutch. It is set up for, I believe, about 12 thousands clearance when all set up and installed. If the clearance is in excess of that, that can have an effect on whether it operates or not. A bench test will tell you much, as stated above. Set it up. put power to it, and it should kick in. If not it may be a bad clutch. This assumes that there is power to the clutch, the interlock module is not an issue, and everything up to the clutch itself is correct.

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The last time I saw a coil like that, much of the wiring itself was visible. Looks like it is time for a new clutch. I have never looked into a possibility of rewinding the coil. Figured that was largely a lost repair option with the cost of new clutches coming in from overseas. I worked on a sunstar and had a similar problem. I replaced the clutch with an aftermarket, none adjustable type. The pulley was a little larger diameter, which makes the blades spin a little faster. Much less expensive than a simplicity clutch.

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As Levi suggested, I hooked a battery to it by running wires from the battery to the wires coming out of the PTO.

Battery.JPG

It locked up, and I was able to pick it up by the pulley.

Pickup.JPG

I guess that means the coil isn't the problem.So, I adjusted the air gap to .015 at all three spots per the manual that Rich posted.

Feeler.JPG

I put it back on the tractor, but it still doesn't engage.I'm again thinking it's some type of electrical problem. But, when I turn the switch on, my tester is showing that there's power at both wires where they exit the PTO.

Power.JPG

Power 2.JPG

Since there's power all the way up there, I'm guessing it's not a bad switch or a bad connection somewhere between the switch and the PTO.I'm at a loss. Anybody got any more ideas?

Battery.JPG.00e27ce15ee6869260b1fb18010124db.JPG

Pickup.JPG.f8f3ba3d4f581e8f26d651e19fe4c6e4.JPG

Feeler.JPG.c04914b2ceb91080e50c3c956eb6a277.JPG

Power.JPG.eb2789e518233e8b82e56d56076b8ec5.JPG

57e05eb4229de_Power2.JPG.20d8d0bdd72a5da62762262f102db865.JPG

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Is the power good power, and is there a good ground? If you have a so-so connection it may be enough to light a test light, but not to engage the clutch?

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Levi:

I ran the black wire coming from the driver's left side of the pto to a grounding point. I ran the yellow wire coming from the driver's right side of the pto to the switch. Then I ran a hot lead to the switch.

There's 5 prongs on the switch. 2 of them accept a 2 prong connector with blue wires coming off of it. That wires in the safety sensors (won't start if pto engaged, etc.). I bypassed this. (Not gonna say how, since that's a no no on a lot of sites; not sure about here). The other 3 prongs accept a 3 prong connector. I did away with that connector. I ran the hot lead to the center prong, and the yellow wire coming from the pto to the bottom prong.

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Glad you got it going. I found a pretty good troubleshooting guide for Warner front ptos. If you'd like a copy, PM me. It's a twelve page pdf. Good stuff.

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I'd agree that you probably fixed a bad ground. Those test lights can be a demon in disguise sometimes. It doesn't take much to get enough of a ground to light that bulb if you have power coming down. Or you aren't even using the same ground as that circuit so you don't think to check the ground associated with the hot wire you are testing. Don't ask me how I know these things wah

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  • 2 weeks later...

Well, I guess I spoke too soon when I said I had it fixed. Was mowing Thursday night when I noticed a faint whiff of what smelled like the clutch rubbing. I stopped the tractor and looked, but didn't see anything wrong. Went to re-start the tractor, and it acted like the battery was really weak. Re-charged the battery, and it worked fine again. Tested the battery, and it's ok. My guess was that it's a problem with the stator plate. Pulled it apart, and noticed that the wires were frayed. The copper on both leads was showing and worn nearly in two:

Stator plate.JPG

I tried splicing the wires, re-shrink wrapping them, and putting it back together. It's doing the same thing - tractor runs fine, but after I operate it for a while if I shut it off and try to re-start it the battery seems weak. And, the PTO doesn't always work. I guess I'll try replacing the stator plate and see if that does it. Maybe the frayed wires rubbing together over time damaged the stator plate itself? I really hate electrical problems. Electricity is a sorcery which I will never understand.

57e05ecfadae6_Statorplate.JPG.a9ca0b8b23d4807f602dbf7c2f64413e.JPG

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