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ericg
04-28-2007, 06:59 PM
I have a Kohler 20hp twin cylinder horizontal shaft motor in a 48" Walker mower. The engine would not turn over so I charged the batery and then load tested it. The battery failed the load test so I replaced it. The engine started right up but the voltmeter on the instrument panel is only reading slightly higher than 12 volts. I placed a voltmeter on the battery with the engine running and it is reading 12.6 volts. Is this acceptable? If not, what wires do I have to check to determine if the regulator is functioning properly.

Restrorob
04-28-2007, 07:33 PM
When you performed the test was the engine at FULL throttle ?

ericg
04-28-2007, 07:47 PM
Restorob, thank you for the quick reply. The voltage at the battery went up less than a half of a volt from idle approx 3600 rpm. The max I could get from the charging system is 12.65. I checked all of the grounds and they are good.

Restrorob
04-28-2007, 08:29 PM
Un-plug the voltage regulator and put your multimeter on AC volts, Put a test lead on each of the white wires. Start the engine and run at full throttle, You should get 28 or more volts.

If lower than 28 the stator is bad.

If you do get 28 or above AC volts check the ground wire/strap on the voltage regulator for corrosion, Also check for battery voltage on the center wire in the regulator plug with the key in the run position.

If stator test OK, Regulator ground is good and there is voltage to the center regulator wire replace the voltage regulator.

ericg
04-28-2007, 08:50 PM
Thanks so much Restorob. I will check this tomorrow. This is a great site and it is members like yourself that go above and beyond to help.

Restrorob
04-28-2007, 08:59 PM
Thanks ericg !

It was no problem.....

fixer67
04-28-2007, 11:54 PM
I worked on Walkers every day. Check the ground lead at the voltage regulator. Also with the engine off but the key in the run position check to see if you are getting 12 volts DC at the voltage regulator on the middle lead wire.

fixer67
04-29-2007, 12:07 AM
http://www.lawnsite.com/showthread.php?t=123152&highlight=Kohler+charging

This should help.

Restrorob
04-29-2007, 09:13 AM
Check the ground lead at the voltage regulator. Also with the engine off but the key in the run position check to see if you are getting 12 volts DC at the voltage regulator on the middle lead wire.


check the ground wire/strap on the voltage regulator for corrosion, Also check for battery voltage on the center wire in the regulator plug with the key in the run position.

Hmmm.....Did I miss something here. :confused:

ericg
05-12-2007, 04:55 PM
I finally got the machine back from the dealer. He said that a leaking engine seal caused the stator to become shorted to ground. He replaced the stator, engine seal and regulator and charged me $300.00. He gave me the stator and showed me with an ohm meter that it was shorted to ground. Has anyone ever heard of a bad engine seal causing this problem with the stator? Again, thanks to everyone who responded to my post. This is a great site.

Eric

Restrorob
05-12-2007, 06:23 PM
Has anyone ever heard of a bad engine seal causing this problem with the stator?


Never in my (next month) 16yrs.

Sounds like you got ripped.
Stator $70 range
Regulator $40 range
Seal $3 to $4 range

$186.00 labor, Parts shipping ? tax, For 3/4 to 1 hr. work.....

ericg
05-12-2007, 10:35 PM
RestoRob, thank you for your honesty. Withiut a gauge to go by, I was unsure if the price was fair or not. The dealer stated that he had to remove the motor from tha machine (a Walker) to effect repairs, which took time. I guess I cannot understand how an oil leak could cause the stator to go bad. I saw the meter when he tested the old stator. There was .002 ohm from one stator lead to the other and 8 ohms from the stator lead to ground.

Restrorob
05-12-2007, 10:50 PM
OOPS, I mis-took the walker for a walk behind :hammerhead:

That really was a fair price in that case....

ericg
05-12-2007, 11:07 PM
RestoRob, do you think that there is any coincidence between the oil leak and the stator going bad. The 20 hp Kohler has about 5500 hours on it with no other problems. We have seven riders. Six are made by Walker, one by ExMark and one by Scagg. We have had good luck with the Kohler engines and one of the other 20hp units has 6700 hours. We change the oil every week, blow down the machines daily and are in tune to anything that requires repair and take the machine out of service as soon as possible to effect repairs.

Restrorob
05-12-2007, 11:25 PM
IMO, I believe thats all it was is a coincidence. I have never heard of or seen oil take out a stator. The way you speak of taking care of this equipment did anyone notice a oil leak ?

Bill Kapaun
05-13-2007, 01:02 AM
"There was .002 ohm from one stator lead to the other and 8 ohms from the stator lead to ground."

.002 OHM?
That's nearly impossible to measure with mere mortal test instruments. Normally you get more radio interference than that.
I think we call that a "short".

ericg
05-13-2007, 10:32 AM
RestoRob, there was evidence of oil "seepage" from the lower end but nothing that necesitated taking the machine out of service. In fact, the stator had a fair amount of blackend oil and dirt on it when the dealer showed it to me. I guess a small amount of oil would not show on our daily oil checks. It seems like a seepage of oil attracts dirt which makes it look worse.

Bill, the meter that the dealer used was a Fluke 77 and it was set to auto range. I saw .002 on the stator to stator lead and 8.00 on the stator lead to ground. In fact, the dealer showed me the specs from the Kohler manual which is .064/0.2 for the ohm's test of the stator to stator lead and infinity for the stator to ground test.

Restrorob
05-13-2007, 11:38 AM
Well Eric,

This is why I don't believe the oil took out the stator.

The service center I work for is also a Polaris ATV/Ranger Dealership. On all of these ATVs the $340 stator is behind the water tight recoil housing/assembly. When a crank seal starts leaking on these it fills this recoil/flywheel area with oil thus the stator is 'swimming' in oil until the level reaches where the rope exits (about 3/4's of the area) before the customer realizes they have a problem.

On top of this recoil housing is what looks like a oil fill plug but is not, It is removed for using a timing light to check spark advance. I have seen customers remove this plug and fill this area with oil thinking it was low.

I believe it was just time for this stator to check out and they just done you a favor by doing the job right and replacing the leaking seal in the process.

ericg
05-13-2007, 12:44 PM
Restorob, you have a way of making complicated things seem so easy to understand. Thank you again for taking the time to review and comment on my charging issue. It is truly a comforting feeling knowing that there are people like you who are willing to offer guidance to those of us who are not subject matter experts.

Bill Kapaun
05-13-2007, 03:58 PM
"the dealer showed me the specs from the Kohler manual which is .064/0.2 for the ohm's test of the stator to stator lead and infinity for the stator to ground test."

Eric, obviously the stator is shorted to ground as per the 2nd spec.
The point I'm making about .002 OHMs is that it's nearly impossible to measure accurately.
I used to build oceanographic instruments and used some rather spendy Flukes. Just moving the leads around a bit results in bigger errors than that. They act like a radio antenna (to a point) and different orientations make the readings jump all over. The leads themselves have more resistance then that.
"Modern" multi meters use such a TINY amount of current to measure OHMs, that often "outside influences" are often overlooked.
Glad everything is "squared away".

PS- reminds me of a story where a lab technician was calibrating tiny "gram weights". He checked the weight on the very expensive "calibration scale" and then glued the thick, aluminum calibration sticker to the weight.

Fordsflylow
08-20-2009, 11:34 AM
Un-plug the voltage regulator and put your multimeter on AC volts, Put a test lead on each of the white wires. Start the engine and run at full throttle, You should get 28 or more volts.

If lower than 28 the stator is bad.

If you do get 28 or above AC volts check the ground wire/strap on the voltage regulator for corrosion, Also check for battery voltage on the center wire in the regulator plug with the key in the run position.

If stator test OK, Regulator ground is good and there is voltage to the center regulator wire replace the voltage regulator.

When checking for the "battery" voltage/center wire does the engine need to be running?

Restrorob
08-20-2009, 06:55 PM
When checking for the "battery" voltage/center wire does the engine need to be running?

It can be but doesn't have to be, Your checking with the key switch in the run/on position......