Hooked up backwards jump start

Qweaver · August 09, 2015, 09:14:45 PM

I did not check the stator. OK that would be between the AC leads? And resistance in ohms?

John Mc · August 10, 2015, 09:22:23 AM

Yes, that's between the stator leads. When running, it's AC volts (I forget voltage range, but mentioned it in another thread). I would first check with the engine NOT running. Disconnect leads from regulator. Measure resistance between two stator leads (probably the two that are the same color).

First, check each lead to ground, it should be infinite (even a cheap ohmmeter will work for this). If it reads 0 ohms or something low, the stator is shorted to ground - a problem.

You may have to borrow a high-end ohmmeter to check the resistance between the two stator leads, and make sure it's calibrated properly. If the resistance measures 0.1 or 0.2 ohms, the stator should be OK. If the resistance is infinite or high (even checked with a cheap ohmmeter), the stator is open = a problem. If the resistance is 0 ohms, the stator is shorted out -- note a cheap or even a decent ohm meter for other purposes may not reliably measure the difference between 0 and 0.1 or 0.2 ohms. Make sure leads are clean and meter is calibrated to 0 when meter leads are shorted together.

Qweaver · August 10, 2015, 10:17:23 AM

I just checked the stator and resistance is infinite on both ac leads to ground AND ac to ac. So the stator is open = new stator and I probably fried the new regulator also. I'm not understanding why the stator windings show continuity to ground. I gotta get a book on this!

Jeff · August 10, 2015, 10:38:51 AM

These two topics have been merged together. If someone in the future has this or a similar problem, and is trying to find an eventual solution, and that solution is reached in a topic not connected to the original topic where the problem was first discussed, it is a disservice to that future member. We must always remember, the Forestry Forum is not only about getting help, it is about giving help as well, and that sometimes is done via the solution of our previous problems.

Jeff · August 10, 2015, 10:41:26 AM

Have you called Sparks?

John Mc · August 10, 2015, 11:36:46 AM

Quote from: Qweaver on August 10, 2015, 10:17:23 AM
I just checked the stator and resistance is infinite on both ac leads to ground AND ac to ac. So the stator is open = new stator and I probably fried the new regulator also. I'm not understanding why the stator windings show continuity to ground. I gotta get a book on this!

If resistance is infinite to ground, you do not have continuity to ground -- that would read zero resistance to ground. So it's not shorted to ground, which is as it should be. Howver, the AC to AC is open, which means somewhere in there either one of the leads came disconnected inside the engine, or the winding is broken.

There are tests you can do on the regulator, but that's beyond my experience. I small engine shop may have a regulator tester, which would simplify checking it out - but who knows how much they'd charge you to test it.

Qweaver · August 10, 2015, 11:52:36 AM

"If resistance is infinite to ground, you do not have continuity to ground" I'm just confused. With the meter set to
RX1 the needle goes all the way to the right when I connect between the AC connectors and ground. Also to the right when I connect from AC to AC. I thought that showed continuity? I think I'm just miss using the terms.

Qweaver · August 10, 2015, 11:58:12 AM

I learned this all at one time but too many years ago.

Qweaver · August 10, 2015, 12:30:02 PM

Thanks Jeff! I just got off of the phone with Sparks at Woodmizer and he got me straighten out. What a clear logical speaker he is.

John Mc · August 10, 2015, 12:58:18 PM

Quote from: Qweaver on August 10, 2015, 11:52:36 AM
I'm just confused. With the meter set to
RX1 the needle goes all the way to the right when I connect between the AC connectors and ground. Also to the right when I connect from AC to AC. I thought that showed continuity? I think I'm just miss using the terms.

I'm not sure which way is which on your meter. If you connect the two leads on your meter to each other, you now have "continuity" between the two meter leads (i.e. a continuous circuit. Another term for this is that you have "shorted out the leads"). Whichever way your meter swings should be zero ohms. If it's swinging the same way when you connect one lead to a stator wire, and one to ground, your stator is shorted to ground (you have "continuity" to ground"). That's what you don't want when checking your stator leads against ground.

When you check from one stator lead to another, the meter should swing the same way as when you short out the meter leads to each other, but it should not swing quite as far (the difference will be too small to see on most meters).

Sounds as though you've already got this figured out. Sorry if my description has been less than clear. 35-40 years ago I was seriously into electronics/ham radio, and that sort of stuff. It's been a while since I messed with it much.

Qweaver · August 10, 2015, 01:49:33 PM

Thanks for your help John. I've got it figured out now. I just ordered a new stator and regulator. @ $60 for the pair and a bit of work to replace the stator. I'll pull it in the shed and get it apart today. Hope I don't make that dumb move again. I hope the flywheel comes off easily. :

Hilltop366 · August 10, 2015, 02:01:13 PM

Flywheel nut torque needs to be correct when reinstalling on most small engines, if not enough torque the flywheel will shear the key then all you get is a muffler full of gas and the occasional backfire when trying to start.

Hope the repair goes smoothly!

Jeff · August 10, 2015, 03:22:34 PM

Did Sparks diagnosis the problem? They don't call him Sparks for nothing.

He's the go to guy for anything Wood-mizer electrical.

John Mc · August 10, 2015, 03:24:33 PM

Quote from: Hilltop366 on August 10, 2015, 02:01:13 PM
Flywheel nut torque needs to be correct when reinstalling on most small engines...

I have not checked, but I assume the manual I linked to earlier would have the proper torque for the flywheel.

Good luck with the repair.

Qweaver · August 10, 2015, 04:17:37 PM

Yep, Sparks gave me the right info AND emailed me the manual. I'm good to go now. Great service from Wood-mizer! Just got to get the saw in the shed before the rain gets here.

Qweaver · September 09, 2015, 05:59:55 PM

All right! We are making 14 v again! The stator was fried. I replaced the stator and regulator and all is now well. A lot of stuff has to be unbolted to get to the stator and it took me most of the day and a trip to the parts store for a puller that would work. I've got three sawing jobs to do so just in time. $55 stator, $20 regulator, $15 puller = $90 for stupid move.