Author Topic: Help to determine stator amps  (Read 7085 times)


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Help to determine stator amps
« on: May 31, 2014, 02:12:46 PM »
I'm helping an Amish neighbor with a Kohler CH25S motor. He bought it from someone who ripped out the starter and charging system (stator and regulator/rectifier), and my neighbor would like to put them back in. The original parts are missing. A replacement starter was easy to install and it works nicely. I bought a used stator supposedly from a CV15S. It generates around 40v AC, which I measured by putting a voltmeter across the stator leads. The rectifier/regulator, however, is giving me trouble. I bought a used one, installed it, but no DC voltage from the + lead. I returned it, bought a new one, and installed it with the same result: no DC output from the regulator/rectifier. Since this happened twice, I'm afraid it's me who's burning up rectifiers and not that I'm consistently buying bad ones. However, I can't imagine how I would be burning them out since I didn't get far enough to hook up the output to a battery. In other words, there is no load on the charging system except for my voltmeter. In any case, I'd like to know if there's a way to determine whether my stator is a 15A, 20A, or 25A unit. Lots of guys say mixing, for instance, a 25A stator with a 15A rectifier would blow out the rectifier immediately. My guess is that my stator is 15A, but I can't tell, and in my unlearned and inexperienced opinion, it shouldn't matter anyway if there's no load! Only when I draw more than 15A through the rectifier would it matter. So back to the real question: can I tell by looking at the stator how many amps it's made for?
« Last Edit: June 03, 2014, 09:43:24 PM by csigona »


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Re: Help to determine stator amps
« Reply #1 on: June 01, 2014, 06:01:52 PM »
Here is a link to the service manual for the Kohler CV15S engine:

Kohler CV15S Service Manual

The most common charging system for this engine is the 15 amp, but it also came with a 3 amp unregulated charging system. I will post the picture of the 2 possible stators below, but its hard to see a difference from the photo's provided in the service manual. It does say the wires coming from the 3 amp stator are yellow and black. I didn't see a color code for the wires used on the 15 amp stator. Study the manual and look at the two different wire schematics for both charging systems. If you still can't determine which stator you have, than call Kohler technical support. Kohler engines has excellent technical support, so they can probably tell you the information you need to determine which stator you have. If you still can't identify your stator, than post a picture of the stator on this forum, and I will try and figure out what stator you have.

I think Kohler may have used the same laminated iron core for both the 3 and 15 amp stators, but Kohler used more copper windings for the 15 amp. If you look at the wiring diagram the 3 amp stator may have a diode in the leads coming from the stator, and the 15 amp stator does not.

If you prefer to contact Kohler through their online technical support, than here is the link:

Kohler Contact Page[url]

« Last Edit: June 01, 2014, 08:15:32 PM by smallengineshop »
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Re: Help to determine stator amps
« Reply #2 on: June 03, 2014, 09:30:37 PM »
Thanks for the advice. The pictures seem to show that the 3amp stator only has windings on some of the lugs, while a 15amp stator has windings on all of them. If so, mine is 15amp, and I'm starved for ideas. My next step is to secure some cheap ($1) Chinese power rectifiers for testing, not for actual use. If indeed the problem is mine, and I haven't just bought two bad Kohler rectifiers in a row, I don't want to keep burning out expensive Kohler versions while I figure it out. After working out the problem, I'll put in a third Kohler rectifier/regulator.
« Last Edit: June 03, 2014, 09:50:08 PM by csigona »

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Re: Help to determine stator amps
« Reply #2 on: June 03, 2014, 09:30:37 PM »