View Full Version : Kohler 23hp Stator question...

09-12-2010, 03:32 PM
Hey guys, first post, long time lurker.
Here's my deal. I have an Exmark Lazer Z 60"(awesome machine). It's 7 years old, w/287 hours on it. I just bought it, and noticed I was having charging issues. At first I thought it was a bad battery, as it was old.
I replaced it, and still not charging.

I have checked the stator, and am only getting 11-18volts. I ohmd it out, and the windings show .2ohms It's not shorted to ground.

My question is, should I still go with a new stator, or is there a different problem I may be overlooking?

I hate shot-gunning parts at stuff, so I'm just trying to rule out anything else.

09-12-2010, 04:44 PM
I'm not familiar with the newer stators but I would think you ought to have at least 30 VAC across the stator leads with the stator lead disconnected from the regulator/rectifier.. Your resistance across the stator lead at .2 ohms is acceptable. You should also check resistance from each stator lead to engine ground. If you have any resistance or continuity, the stator leads are shorting to ground.

You can normally check to see if you have DC output by checking voltage across battery terminals with engine not running then with engine running. If the reading is higher with engine running you have at least some output. In addition, remove the wire that goes from the B+ terminal to the switch at the switch. You should have 13.5-14.5 from that lead to the negative battery terminal with the engine running.

You could go to Kohler's website to download the manual for your engine and check their trouble shooting guide for the stator.

09-12-2010, 05:08 PM
I have the manual(thanks tho)My DC output is right around 12.9 at full rpm.

My no load AC(stator) output is less than 20vac. I am not sorting to ground. I'm an HVAC tech, and with Fan motor windings, they can show good windings, but when load is applied they heat up, and open up. I'm wondering if this is my problem.

I have also read somewhere that the magnets come off the flywheel. I don't or haven't heard any noises that would indicate such.

09-12-2010, 06:32 PM
Dutch is right with 30 + AC volts, Pull the flywheel before chasing down a stator and use a puller for removal. If the magnets aren't broke loose they could be using the old pry-bar and hammer method.

09-12-2010, 06:47 PM
I'm leaning towards flywheel. I ohmd the stator and regulator, both seem good to go.
Stator was showing .2-.3 ohms. Output voltage is consistently less than 24v.a.c.

I'll pull the flywheel later this week.

09-12-2010, 07:05 PM
It's pretty rare, in my experience at least, that when a flywheel magnet has been lost it's pretty rare when damage has not occurred to the stator. Good luck.

Rob, you are correct on the prybar and hammer, especially for someone who does not do the job regularly. When I use this method, I am careful to use the extreme end of the prybar against the block and a closer part of the bar on the very edge of the flywheel--in other words lifting on the prybar rather than pushing down.

09-12-2010, 07:12 PM
Thanks for the advice guys. I'm hoping the stator isn't damaged, but with my luck, I'm sure it is.

09-12-2010, 10:00 PM

On these Kohlers it's not the prybar that pops the magnets loose, It's the sudden shock from the hammer hitting the crankshaft/bolt.

Believe it or not rust forms under the magnets through the epoxy they use to bond them in, The least amount of shock once rusted pops them loose.

09-12-2010, 10:18 PM
I don't doubt that it can happen in that manner, Rob. I'm sure you have seen a lot more of the Kohler magnet problem than I have but I was in a shop envoirnment for 5 or 6 years and don't recall it ever occuring. On the magnet failures I observed the magnet(s) had come loose while running and the conclusion was that it was an adhesive/rust problem that caused the problem.

I'll put that in my memory bank for future consideration.

09-12-2010, 10:35 PM
don't recall it ever occuring.

Well Dutch, I hate to admit but in my younger days replacing a top crank seal I used the prybar method. This was one of the first Commands I worked on, I know I popped the magnets loose because I drove the unit into my bay and there was no damage to the stator or other magnets.

After having to buy the customer a new flywheel, My prybar and hammer stays in my toolbox......

09-13-2010, 07:57 PM
Well, apparently my day is to get worse. I can't read the spec numbers on my mower, and the mower Serial number plate is gone.

If any of y'all can help me out here, that would be great. It's an Exmark Lazer Z 60" ultracut deck. I can read the serial number on the motor, but outside of that, I'm hosed.

09-13-2010, 08:36 PM
I can't find the edit button here.

Near as I can decipher, my spec number is 76550?
I have searched this mower high and low, and CANNOT find the serial number, or the remnants of one. No tag, no nothing.

I am the second owner, as far as I know, I bought it from a minister. I can't find his number to see if he has the tag. So hopefully I can get what i need.

09-13-2010, 09:50 PM
The 76550 spec is shown as being used on a Exmark so that should be it, What did you find the problem to be ?

09-13-2010, 09:59 PM
I haven't taken the flywheel out yet. I wanted to make sure i could find the flywheel, and for that I had to guess at my Spec number.

I triple checked my stator today. It OHMS out perfect (.2-.3 Ohms) It is not open to ground.

I ohmd my regulator out. I showed continuity thru it.

My stator out put voltage starts at 24vac, then quickly drops to 12 vac. I went to my dealer to price the flywheel(I'm having problems finding the Part number). He was convinced it wasn't the flywheel.

I can't down this mower, it's my only tractor, so I'm afraid It might be a week or two before I can do something.

09-13-2010, 10:32 PM
I don't believe your problem is the flywheel either, If a magnet did come loose it would wipe the others out along with the stator as Dutch mentioned he has seen same as myself.

You performed the stator AC output test and it has failed, That's where I'd be heading. Just because your shown a closed circuit through the stator doesn't mean it couldn't be internally shorted, It could be shorted and only using half or quarter of the windings.

You could still have a problem with the regulator since there's no ohms test for it.

Testing procedure is check for battery power (12.5 VDC) on the violet (center) wire on the regulator with the key in the run position, Check the ground strap/wire mounting points at the regulator mounting screw and flywheel cover screw for corrosion and tightness.

Unplug the regulator and perform the running AC output test on the stator, If the stator passes and you have power to the regulator with a good ground path and still no charge at the battery the regulator is faulty.

Flywheel part # 24 025 04-S List at $171.14
Stator part # 237878-S List at $60.06
Regulator part # 41 403 10-S List at $56.68

Good Luck

09-13-2010, 10:46 PM
Good to go then. I have checked the stator (load/no load) and it has shown 11volts 3x. I will replace the stator, and then check the regulator. I appreciate the input. This is the first V-twin I have worked on, so I am cutting my teeth as I go.

09-15-2010, 02:40 PM
I dont know how much you use the mower but alot of dust can get caked around the stator. We take the flywheel's off of our 26 EFI's at the end of every season and clean them really good.

04-02-2011, 08:58 PM
hey guys, I have a Lazer z 52'', Kohler 23hp Vtwin. I have a charging problem.. I pulled the flywheel, and the magents wer perfectily stuck to the stator! I clean the wheel and appox them bk on I did the stator test you described and the ststor was reading 14acv.. humm. I put a brand new stator in OEM. and the same 14ac-v can up. I hate to think I have a bum new stator. many hrs. and research....Can any one other any help?

04-02-2011, 11:06 PM
I clean the wheel and appox them bk on

You can't just epoxy magnets back on, If you have the same test results with a new stator I'd put a new flywheel on.

04-04-2011, 02:19 PM
I took great time to clean, inspect, and measure the magnets before appx them on to the flywheel. the tests were 14ac-v at the stator, so i replaced it. same test, same results 14.. my question is is it possible the magnets have lost much of their magnitisum? or is my new stator defective?

04-04-2011, 09:15 PM
OK adam1,

Take your multimeter and put it on ohm's scale, With engine off and regulator un-plugged put your test leads across the stator wires. You should have a resistance of 0.064/0.2 ohms, Now take one test lead off one of the stator wires and touch it to the center laminates where the mounting holes are, You should have infinity ohms (no continuity). If both stators are with-in these specs Replace the Flywheel......

04-05-2011, 07:54 AM
Thank you so much for all your help. this is a great site, and has such vaule. thanks again!

04-08-2011, 06:34 PM
Well, I'd OHM the stator out. Check for resistance between the coils. Mine turned out to be a bad flywheel and stator. I paid the dealer(stupidly) to replace them Cost me $500.

If the stator ohms out, and shows nothing to ground, I'd guess your flywheel. I talked to the Kohler tech guys, and they say that a majority of charging failures are flywheel related.