Docwheelhorse 2,718 #1 Posted March 23, 2012 Hello all, my C121 quit charging about 6 months ago and I finally got sick of hooking up charger just to use the tractor. I bought myself a puller and got the flywheel off with no issue.....stator is now off engine and on my bench. I need help figuring out how to test it on the bench. I had checked before pulling the engine apart and was getting above zero but less than 5 volts AC at full throttle. Upon pulling the flywheel I found all the magnets still in place and strong enough to hold a screwdriver. Sparky came over and we tested the continuity and found that between the two leads was fine (continuity) and between each lead and the steel mounting ring there was nothing.... that all seems perfect. I see no damage to the stator at all---but still no juice. What gives?? Thanks Tony Share this post Link to post Share on other sites
stevebo-(Moderator) 8,437 #2 Posted March 23, 2012 Where is SOI when you need him?? Share this post Link to post Share on other sites
Docwheelhorse 2,718 #3 Posted March 23, 2012 LOL.... I sent him a PM asking for him to review this post! Tony Share this post Link to post Share on other sites
oldredrider 2,553 #4 Posted March 23, 2012 Hey Tony, This past Fall I ran across a similar problem on a C-160. Long story short, somewhere along the way, one of the previous owners had the magnets let go in the flywheel and just "willy nilly" glued them back in. The poles were reversed on 2 or 3 of them; hence low AC output. Since it quit charging on you about 6 months ago, this ain't your problem but I thought I'd throw it out there for someones "future reference". You should try another stator to see if that fixes the issue. 1 Share this post Link to post Share on other sites
Save Old Iron 1,568 #5 Posted March 23, 2012 Hey Tony, Paul is on the money with his comments about the magnets. The flywheel should have 6 magnet segments. Each segment has three magnetic poles and there are two different magnet configurations in each flywheel. One magnet type will have a North - South - North (NSN) pole configuration and the other type will have a South - North - South (SNS) pole configuration. Each flywheel will have 3 magnets of each pole configuration. The trick is to have 3 of each configuration and configurations are alternated as they are placed into the flywheel. (click on images to enlarge) The magnet configurations can be checked with a small magnetic tool / screw retriever. It is not important if the retriever magnet is polarized as North or South. It does not matter which flywheel magnet you start with. Just comfirm all facing edges of all magnets have a different polarity from their "next door neighbor". fn the case where somewhere replaced cracked or missing magnets with improper polarity types, you could end up with 2 of one type and 4 of the opposite [p;e type. The magnets would look fine but incorrect polarities would yield significantly decreased output from the stator. Take the retriever and place it near the end of one magnet, The retriever is either going to be attracted or repelled from that particular spot on that particular magnet. The key to proper magnet alignment in the flywheel is making certain boths of any given magnet has a neighbor magnet of opposite edge polarity. Correct alignment of magnet segments in a flywheel will look like the diagram below misplaced magnets will map out like this 1 1 Share this post Link to post Share on other sites
Docwheelhorse 2,718 #6 Posted March 23, 2012 Hi--well I will check the magnets but don't think that is it.... this unit USED to charge like crazy and then it quit one day.... I replaced the regulator and it worked for another couple months. Then it started doing the charge for 5 minutes, not charge, charge for 5 minutes thing as I would be mowing. Finally no charge period and I checked the AC output and got around 3.8 VAC. I will look at the magnets and then dig around for a stator and try that... Thanks for the info Tony Share this post Link to post Share on other sites
Save Old Iron 1,568 #7 Posted March 23, 2012 just for giggles, you could cut back the stator wires and put on new push terminals. it is possible a high resistance at the terminals is causing voltage drop On closer inspection of the stator pic you posted, do I see a possible broken wire, and a few segments with bare copper wire exposed ? The side you have pictured here is the side facing the engine. Are there additional shiny copper spots on the front side too ? The wiring in general looks a little dark and crispy, possibly from overheating ? "ohming out" a stator on the bench is difficult and usually inconclusive. A good stator will have less than 2 ohms resistance. A normal ohm-meter has great difficulty with measuring ohms in that region. A good stator and a shorted stator may not display any significant difference in reading on a multimeter. Many digital meters have great difficulty reading resistance in an inductive winding such as a stator. The best chance you have at obtaining an useful reading is to perform the reading on an analog meter with an Rx1 scale. Share this post Link to post Share on other sites
pfrederi 18,520 #8 Posted March 23, 2012 You mentioned that it used to charge for short time then quit. Makes you think that when heated up there is is a change in the stator...Either an open or a short. May want to warm it up a bit in the oven then do your multimeter test... Share this post Link to post Share on other sites
Docwheelhorse 2,718 #9 Posted March 28, 2012 Hi SOI / Everyone, well.... I put a good used stator out of an 8 into the 12 and fired the engine up, I'm now getting 28-35 VAC depending on how many RPM's I give it... Is this normal? Now the next problem---I hooked the leads up to the regulator and re-started the engine and NOTHING..... I guess the regulator must of been wrecked somewhere along the lines too. Tony Share this post Link to post Share on other sites
rmaynard 16,141 #10 Posted March 28, 2012 Tony, 28 to 35 VAC is good. Assuming that you are hooked up to the correct terminals on the rectifier/regulator, and the connections are clean and tight, and the R/R is properly grounded, you should be getting about 14 VDC at the B+ terminal. If not, I'd say the R/R is toast. Share this post Link to post Share on other sites
Save Old Iron 1,568 #11 Posted March 28, 2012 Hi SOI / Everyone, well.... I put a good used stator out of an 8 into the 12 and fired the engine up, I'm now getting 28-35 VAC depending on how many RPM's I give it... Is this normal? Tony, 35 VAC is fine for the AC input to the regulator. The other stator did look a little toasty with the darkened windings. Drawing too much current from the stator could have been a result of a short within the regulator assy or possibly too great an amperage draw thru both the stator and regulator. Prior to swapping the regulator, run a quick jumper wire from a non oxidized or non-painted section of the regulator case directly up to the battery (-) negative terminal. You may have to clean one of the regulator case fins or possibly the area near the fastening bolts holding the regulator to the chassis. If the regulator output jumps up to 14.5 "ish" volts, investigate why the regulator is not picking up a good ground from the chassis. Example of poor ground thru chassis - rust and paint prevent this regulator from grounding properly thru the mounting plate to the chassis ground In addition, confirm the terminals on the reg are clean (silver and shiny, not rusty and dull). I did not understand what you meant by "re-started the engine and NOTHING". I guess the engine started but you didn't see any charge on the ammeter? Please confirm what you mean by "nothing". In a "key on - engine off" state, the wiring from the B+ reg terminal to the ignition switch should at least allow battery voltage to reach the regulator. Monitor the B+ terminal, when you start the engine, the B+ terminal should jump from 12.6 VDC up close to 14.5 VDC. If you get the 12.6 VDC but no jump to 14.5 VDC when the engine starts, the regulator is most likely bad too. 1 Share this post Link to post Share on other sites
Docwheelhorse 2,718 #12 Posted March 28, 2012 Hi SOI, what I meant was that I started the engine and tested the AC ouput and it was fine, I then shut the engine off and hooked up the regulator and re-started the engine---NOTHING meant that the ammeter didn't move and then I checked the battery with a digital multi-meter and it was 12.6 and wasn't going up at all. I then checked for +12 at the regulator and that was fine and then I checked again for 12+ at the regulator by putting the negative terminal off the meter onto the regulator itself and then to the center terminal (BAT) of the regulator and got 12..... proving that I had ground and power to the regulator but no output. I have never considered electrical issues fun to work on..... but I am close to having this fixed now. Tony Share this post Link to post Share on other sites
Save Old Iron 1,568 #13 Posted March 28, 2012 It is time 1 Share this post Link to post Share on other sites
Docwheelhorse 2,718 #14 Posted March 28, 2012 Man your posts are both chock full of knowledge and funny as heck..... The Squirrel is a riot too!! :laughing-rolling: Share this post Link to post Share on other sites
mdn1081 1 #15 Posted March 29, 2012 I had a charging issue with my C-175. Went through everything you went through as well. I eventually figured out it was in the wiring. Still haven't fixed it properly. Doc Does the B+ on the regulator have to see voltage before it will actually charge? Seems to me that I ran a wire from the + on the battery to the + on the regulator and bam 14.4v? Does that seem correct? Share this post Link to post Share on other sites
Docwheelhorse 2,718 #16 Posted March 29, 2012 Hi--yes that is correct... and I did just that and ran a wire right from B+ to the BAT terminal on the ignition switch and it charged for awhile--I guess I was in the process of cooking both the stator and regulator.... Now that I have a good stator and will put in a good regulator I'm going to look the wiring over.... Tony Share this post Link to post Share on other sites
JoeMonag 1 #17 Posted March 31, 2012 I just had the K341S engine worked on from my 416 to remove the balance gears.. They found all but one of the fly wheel magnets was loose and stuck to the stator. They glued them back in place, but don't recall putting them in any order. I reinstalled the engine last night, and have low out put from my 15 amp alternator. I suspect they may have mis aligned the magnets. Out put is only 10-11 volts AC from the alternator,and 5 volts from the B+ terminal across my vom withother lead to ground. They use gorilla super glue to secure them, any suggestions for a solvent to dissolve the glue, in the event I have the, remove them and re set them correctly? Joe in Norton,MA Share this post Link to post Share on other sites
oldredrider 2,553 #18 Posted April 3, 2012 Apparently the only "solvent" for Gorilla glue is a BFH. Good luck. 1 Share this post Link to post Share on other sites
Save Old Iron 1,568 #19 Posted April 3, 2012 Joe, First things first, Check each flywheel magnet segment to see if they are actually out of sequence. You may only need to reposition 2 of the 6 to get the whole flywheel functional. With 11 volts out, it sounds as though you have some magnets in proper sequence. The TYPE of Gorilla glue used will determine how to remove it. SUPER GLUE usually can be dissolved or weakened by exposure to Acetone. EPOXY can be softened by heat. Not too much heat as magnets can give up their power at temperatures over 400 degrees. Share this post Link to post Share on other sites
JoeMonag 1 #20 Posted April 7, 2012 Well I am happy to report, we found two magnet sements were placed incorrectly. With the help of the Info. from SOI, and my wife's keene sence of observation. we found only two magnets needed to be swapped with each other. I use my B&D electric heat gun on the low 500 degrees setting, I wanted to keep the temp as low as possible so as not to harm the magnet. (Currie temp. of Ferris magnetsis 1043 F) . I heated the segment until the adhesive softened. I brought the fly wheel back to the reapair shop for them to re- bond the two magnets in the proper position. I pick up the fly wheel Monday at lunch, and installed it Monday night after dinner. After I started it the first thing I noticed was the volt meter was reading 14 volts. I took my digital VOM and checked the alternator at full throttle, and read 28 volts AC,the B+ terminal read 13.8 to 14.2. All the charging system components are working to spec. I installed the Johnny-Bucket Jr. this morning. It is great to have a working tractor again. BTW the fly wheel puller Brian Miller recomends is the type you use to remove the harmonic balancer on a GM V-6. By coincidence I had one at my work place. It worked great. Happy Joe In Norton, (SE) MA Joe in Norton, (SE) Ma Share this post Link to post Share on other sites
Save Old Iron 1,568 #21 Posted April 9, 2012 Nicely done Joe. I'm glad some of the stuff in my head can help out once in a while. 1 Share this post Link to post Share on other sites
Coadster32 793 #22 Posted April 23, 2012 SOI....educational, and entertaining as always!!! :thanks: Share this post Link to post Share on other sites
ebinmaine 71,562 #23 Posted January 21, 2022 Occasionally I find an old post on a subject during a successful search and I like to bump it to the forefront so some folks can see it. The occasion here was needing to figure out how to install magnets in a flywheel of a Kohler K582 opposed twin. 1 Share this post Link to post Share on other sites
Wheelhorse#1 1,767 #24 Posted January 25, 2022 (edited) This is a excellent post ,topic.Always learning something new here at RS !! SOI ….excellent info.thx Edited January 25, 2022 by Wheelhorse#1 1 Share this post Link to post Share on other sites
