2072 near disaster
 

Eric and I have a 2072 that has been repowered by a Command Ch18. We have done a bunch of repairs to it mostly to correct PO shoddy work. When done it ran like a champ. The other week Eric was going to use it to haul wood to his house and shortly after he started it he heard a loud bang and saw something fly out from the back of the engine. It squealed like a pig caught in an electric fence. He quick turned it off and it sat for about two weeks in his woodshed till we got to it. Yesterday we removed the gas tank and firewall. I then took off the flywheel shroud and found a bunch of pieces of something sort of stone metal mix. As I pulled several small pieces out I placed them together and they were attracted to each other. Well we then knew what had happened. After the flywheel removal all our doubts and fears were realized. No magnets were left on the flywheel and the stator was killed. Fortunately only a couple of minor gouges to the engine but the stator was toast and the flywheel was done for also. Yes I know that it did not happen without pics so Eric will arrive shortly with them. I was very tempted to look for used parts to repair but found them a bunch cheaper than CC prices at Upstate Outdoor power Equipment.

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So what's your guess that caused this? Was something loose or did a large chunk of debris get in there and smack a magnet, maybe a mouse carried in something? :bigthink:

have seen this before in a kohler v twin wonder what causes it

bad glue that is a very common problem JOE ALLEN

Yep.....

The adhesive that holds the magnets on doesn't last forever. The magnets come loose and ...... yep.

Before we started into the engine I too highly suspected it was either a mouse or squirrel using it for nut storage as it did not have the grass shield on. As far as I can see the only thing in the debris was magnet pieces. It could have been that one magnet left loose and pealed all the rest off and created much havoc. What amazes me was when we finally got it to my garage we tried to start it and it actually started but with more than a bit of grinding noise so we immediately shut it off and disassembled to what you see in the pics.

I have 2 tractors with Commands, would it be a good idea to re-glue the magnets or leave them alone? I am thinking it would be OK, as long as one used the correct adhesive.

It is a know problem...... but it's kind of like the exploding governor gear in a KT or a Mag. Not really worth tearing into on a "just in case". If you want to pull the flywheel and see if all the magnets are firmly attached, then that's fine. But if you try and remove them chances are you will break them. Check it out. If they are tight, leave them alone. Even if you re-adhered them that's no guarantee.

That makes sense, thanks,

Greg

In reading here and on other sites it is a problem but in my estimation is not a real common problem. The magnets are not very easily seen. You have to remove the engine, rear shroud, magnetos, any drive shaft couplers and finally pull the fly wheel. The magnets are spaced around the inside of the fly wheel. They rotate around the stator and unless you do all the above there is no way to see or check them. We have no idea how many hours are on this engine as it was a replacement engine and that happened before we got it. Those magnets spin rather fast and are subjected to centrifical forces possibly up to 3600 rpm. Since they are on the inside of the flywheel that force pushes them tighter to the flywheel so they should last a long time but it is one of the only glued parts in these machines.

Paul, I agree it's not something that happens to all engines or anything. I don't know what percentage of failure rate I would put on it, but it is something that I've personally seen happen about 2-3 times, and on here probably that many. So, it's not a very large failure rate, but it does happen. As for my engines, it's just something I check if I have an engine out where I can look. :beerchug:

I have one more question for the electrical people here. I noticed the purple wire on the DC output pin of the rectifier/regulator is burned and will have to be replaced. Could this have any relevance to the magnet problem or do I have another unrelated problem. The only difference with this machine to another one is I have a Johnny Bucket mounted and it is electrically operated. I do have a new recrifier/regulator coming and have Rolands solid state charging system test and voltage readings to go by when I get the new parts.

Sorry you've run into this, Paul. I just finished looking at Lew's post regarding his 'new' 1641 and one of his pics shows the stator and magnets on the 1641's Vanguard. It looks like the coils are stationary and the magnets are adhered to the inside of a 'rim' on the flywheel. It looks like with that setup the centrifugal force from the spinning flywheel would have the effect of keeping the magnets in place rather than grenading them as the Kohler system seemed to do. Am I seeing this correctly?

Yes you are correct I guess my point was that the glued on parts are the moving part.

It is exactly the same on both motors.

I found his video when I was working on one of my Kohler command singles that was not charging. Its a little Goofy but it does show the magnets loose and how to fix them. https://www.youtube.com/watch?v=DUGK_H-Sulc
I know yours are ruined but you might find it interesting.

Cannon

Final update on the problem. Eric found a parts supplier called Up State which I believe is located in Louisiana. Much cheaper than from CC. Free Shipping too. I ordered the parts online on Sunday and they were here Wednesday morning. That was all good. We got it back together and the tractor reassembled. it started up just fine but was shutting off after a few seconds no matter what we did. We spent all Saturday trying this and that to no avail. Checked the fuel pump and was getting fuel to the carb. Checked the spark and was getting good spark at both cylinders. Air filter was good so we were kind of stumped. We both became frustrated enough to just leave it alone and do some thinking. We just knew that it was a fuel problem but Monday evening we got back to it. After some fuel checks everything checked out. We finally got to the fuel shutoff solenoid and found it was not working. Fixed that with a Sam Mac mod and the engine purrs like a kitten albeit a very large kitten.

whatparts did you order new flywheel?

Yep gt383mag, new flywheel, stater, and rectifier.

that sounds expensive

Yes the stator, flywheel and Rectifier together were close to $300. But the stator was wrecked as some of the wires were broken and several of the tips were bent. The flywheel was ok but had no magnets and the magnets could not be found. The rectifier was an extra expense but it was worth it for the satisfaction factor.