Amperage

[tgranthamfd 29]

How does one tell which amperage system is on their particular horses. Example, While looking for another stator, I saw some rated for 15 amp, 25 amp, and 30 amp charging systems? I even saw some K321 stators with two different amp ratings.

[pfrederi 17,743]

I believe you have to count the number of coils with winding on the stator and compare it the the diagrams in the K series service manual for the various amperages. You can use a 30 amp regulator on any smaller system...but not the other way (no 20 amp reg on a 30 amp stator)

[piecrazy4 0]

:wh: another new section for information :D

[Save Old Iron 1,566]

Terry,

speaking in a general sense ( non Kohler specific)

the number of coils of wire on the stator are a good visual indication of the current capacity of the coil.

the more coils, the more current the system can generate.

the more current you want, the heavier the coil wire gauge has to be to support the current demand. This is similar to house wiring as 14 gauge carries 15 amp max and 12 gauge would be 20 amp max. So there is a 2nd visual clue.

And finally, you can have all the coils and heavy wire you want, but you need magnets on the flywheel to induce a current flow into the coils.

More magnets = more current. Some flywheels restrict the battery charge current by eliminating some of the magnets on the flywheel.

Higher quality, stronger magnets = more current.

If you see a single or possible a double coil with very fine wire wrapped in the coil - that's the "charge coil" part of the stator. Its purpose is exactly opposite of the low voltage high current charging circuit part of the stator.

The "charge coil" is purposefully wrapped with very small gauge wires to allow hundreds of wraps of wire to develop a very HIGH VOLTAGE off the coil.

The sacrifice of using fine gauge wire to develop high voltage is the coil will also develop a very small current (usually in the milliamp range - thousandths of an amp)

These smaller "charge coils" are dedicated to supplying a high voltage to pre-magneto style solid state ignitions used 30 - 40 years ago.

:D

[tgranthamfd 29]

So if I had put the wrong stator on (amperage wise) would it cause missing and popping back through the exhaust? When I changed the stator out, a week or so ago, it stayed charged by didn't run very smooth. Put the old, questionable, stator back on tuned it up, cleaned and adjusted the carb, now it runs smooth but it is not charging properly. With it running at high idle, measured at the stator wires and it went to 18 vac then immediately read open. At the rectifier with the stator wires connected it read 14.??vac. So I am thinking that the rectifier is good and the stator is bad. While not running I got a 0.02ohm reading across the stator wires and open from 1 wire to the metal ring on the stator. The stator windings looked pretty big to me, and all magnets were there, all the way around with about a 1/4" gap in between. Some of the magnets were chipped up some but in tact.

[tgranthamfd 29]

I have been reading and rereading old posts on this subject, if I read correctly I can have a larger rectifier amperage with equal to or lower stator system amperage, is this correct? From the old stator post I had, I am sure the stator is bad and possibly the rectifier, as well. Did some shopping around and found a Kohler 15 amp stator And a NOS 15 amp rectifier, so now I know beyond a shadow of a doubt that my system is now a 15 amp charging system and that the rectifier and the stator are compatible. After next weekend, If things do not work out right, I will be lost and confused more than normal.

[Save Old Iron 1,566]

Terry, I remember you mentioning this a while back - I thought it was a fluke.

On the topic of the stator causing the engine to run "rough" - That's a new one on me.

The tractor does not need the stator connected to the rectifier / regulator to run

sooooo....

I would make sure the battery is fully charged then disconnect the stator connector from the rectifier / regulator and restart the tractor. Does it still run rough ?

If so, its not the stator or rectifier / regulator.

I would be more inclined to believe the engine tins may be shorting out the spark to the plug due to a nick in the magneto wiring. You may have aggravated the spark over when you changed in the new stator.

Get the tractor running and spritz down the ignition area where the spark plug wire enters the engine tins. If the engine starts missing, you may have found the problem.

You might want to try removing the tins and RUNNING THE ENGINE FOR A SHORT PERIOD TIME - 1 MINUTE OR LESS - and spritz down the magneto area with water to see if causes the ignition system to become erratic.

I'm assuming you have already tried a new spark plug.

[tgranthamfd 29]

Chuck, when we originally changed the stator, it was backfiring through the exhaust. We adjusted the points, cleaned the carb, replaced the fuel filter, replaced the fuel line from filter to pump, replaced the plug, and replaced the air filter. The points and carb adjustment seemed to do the most for it, until it got good and warm, then it start again. That stator was the one from my brothers part pile. So I put the original stator back on and did all the VAC checks and it is not putting out enough VAC, but with a quick carb adjustment it is running nicely. I haven't replaced with a new stator yet, so I ordered one, while shopping I ran across a NOS 15amp rectifier and bought it too. What you said about the plug wire makes sense, I will try that. When it was running ruff yesterday we fiddled with the carb, drove it around the barn a time or two, stopped to tell my brother something, and when I idled back up it ran and sounded very smooth and no more cutting out.

[tgranthamfd 29]

:D I don't see any of the ignition wiring going through the tins. Coil to points, outside tins, other coil wire outside tins, and coil to plug, outside tins. The only wires inside the tins are the 2 stator wires.

[Save Old Iron 1,566]

Terry. your right

I don't know why I was thinking M series Kohler when you did say K321.

So knix the spritz on the magneto.

I'm just not convinced the stator is interacting with the ignition and carb mixtures.

The fact that you can get the engine running well by performing carb and points adjustment makes me think that is the area the problem is actually located in.

In the high tech auto world, a defective diode in an alternator can drive an ignition system crazy, but that's in a high tech environment, not a Kohler K.

At this point I would not get all hung up on the stator as the root of your problem. I cannot think of a good reason the stator would cause an issue like you describe. Disconnect the wiring harness from the rectifier / regulator and run the tractor.

If the performance issue returns, its not the stator.

[tgranthamfd 29]

Charged the battery overnight, mowed for the last two hours, killed it for about 10 to 15 minutes while moving cars around, and it started right back up and finished. I was running it just a tad over half throttle, I wonder if I am having a high rpm charging issue. When I checked the voltage at full idle, at the rectifier stator connections, I came up with 18.?? VAC then it immediately went to 1 . , would that not be a rectifier issue? This was at full throttle. Oh yeah, it ran great and didn't miss a beat. :D

[tgranthamfd 29]

Get this, last night when my brother hooked the battery charger to it, he unplugged the wires to the rectifier and I didn't notice it until I loaded it back up and came out to do some more readings on it, and I also found the B+ wire had slipped out of the connector. Went ahead and did some more checks, from B+ wire to ground it read 8.76 VDC running at full throttle. at the stator leads it read 18 VAC and then went to open. At rectifier it kept jumping from 8 to 19VAC. Not running, at stator leads it read 00.2ohms with the meter leads carrying 00.1 ohms. I am leaning towards the stator and the rectifier both being bad. I hope so because I have both coming in a 15 amp set up. Does all this sound about right to all you guys? P.S. with the rectifier unplugged it ran fine and when I plugged it back up it started popping back through the exhaust.

[pfrederi 17,743]

Get this, last night when my brother hooked the battery charger to it, he unplugged the wires to the rectifier and I didn't notice it until I loaded it back up and came out to do some more readings on it, and I also found the B+ wire had slipped out of the connector. Went ahead and did some more checks, from B+ wire to ground it read 8.76 VDC running at full throttle. at the stator leads it read 18 VAC and then went to open. At rectifier it kept jumping from 8 to 19VAC. Not running, at stator leads it read 00.2ohms with the meter leads carrying 00.1 ohms. I am leaning towards the stator and the rectifier both being bad. I hope so because I have both coming in a 15 amp set up. Does all this sound about right to all you guys? P.S. with the rectifier unplugged it ran fine and when I plugged it back up it started popping back through the exhaust.

I think you are on track with the stator being bad...You should get at least 28-30 volts AC on the stator leads. Most of mine put out high 30s one

[tgranthamfd 29]

Well, as stated above, I replaced with new stator, rectifier, and eliminated a twisted wire and tape connection, on the B+ wire. It runs beautifully, although it is still really jumpy when trying to check the ac voltage even on brand new connections. So, I just put the fully charged battery in it, kicked on the headlight, and proceeded to mow, start, stop, and it restarted every time, so far. It has, now, sat overnight with everything connected and I am about to go see if she starts. If it does I am going to call it a done deal, finally. Thanks to everyone

[Save Old Iron 1,566]

it is still really jumpy when trying to check the ac voltage even on brand new connections.

Terry,

try measuring the AC voltage at one of your home outlets.

Set the meter to measure at least 120VAC and be careful when inserting the meter into the wall socket. Keep your fingers clear of the metal probes on the probe body.

If your readings are still "jumpy" when measuring VAC from your home outlets, the meter is probably bad (at least on the AC function).

Otherwise the meter could be poorly shielded and RF interference - from the spark plug wiring - might be getting into the meter body and screwing up the VAC reading.

[Save Old Iron 1,566]

Chuck, when we originally changed the stator, it was backfiring through the exhaust.

Well, I thought about this a little more.

This is pure hypothetical thinking and may register pretty high on the

but it is possible that if the rect / reg assembly were shorted, you could have been applying a fairly high AC ripple voltage on the ignition coil wiring.

HOWEVER, to do this, the battery internal resistance would have been fairly high and that would have shown itself by hard starting or no starting of the engine.

Batteries normally act as VERY GOOD condensers / capacitors and filter out most of the AC ripple presented to them. Only when the battery develops a high resistance from sulfated plates will it tend to pass large amounts of AC voltage without filtering it out.

This high AC voltage going to the ignition coil could have been inducing multiple, ill timed sparks in the combustion chamber and screwing up proper ignition. At other times, the AC may have been preventing some sparks from being created and raw fuel was being dumped into the muffler and igniting on subsequent exhaust cycles.

Again, just thinking aloud.

[tgranthamfd 29]

I to deep for me. but that issue quit when I found that the B+ connector had slipped out of the connector housing, and the charging issues were resolved once I replaced the stator and the rectifier. I don't know if both were bad, but I decided not to take a chance on one or the other. Personally I think both tested weak. I really do appreciate your help through all of this.

[gwgdog66 23]

but it is possible that if the rect / reg assembly were shorted, you could have been applying a fairly high AC ripple voltage on the ignition coil wiring.

HOWEVER, to do this, the battery internal resistance would have been fairly high and that would have shown itself by hard starting or no starting of the engine.

This was happening at times. His Stator was not putting out enough, and his rectifier wasn't passing the tests in the Kohler manual. It made me want to pull what little hair I had left out.

It is running like sweet dream now.