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Craftsman 917.257740: trouble starting/keeping running.

Posted by pet575 Missouri (My Page) on
Sat, May 1, 10 at 18:46

I have a Craftsman tractor #917.257740 which, when I turn the key, nothing but a single "thunk" sound and the engine does not spin. The lights do work. Put the battery on the charger again for about an hour, same problem.

Checked as many leads/terminals as I could. I did find a wire near the fuse holder which had the insulation rubbed off of it and the wire was exposed. I believe this was causing the problem I was having with the fuse blowing. Everything else looked fine.

With a jumpstart, I was able to get the mower running and mowed nearly my entire yard-which is not large. The engine then died on me and I couldn't get it restarted. Jump started again and it only ran for 2-3 minutes then died again.

To me, this eliminates the starter and solenoid. Once it was started, it would not run for more than a few minutes before it dies. Once that happens, there isn't even enough juice in the battery to light the headlights. So that confuses me. I would think that if my alternator was worthwhile, the mower would run until it ran out of gas even without a battery. However, I DID have a car once that had a perfectly good alternator in it but it would not stay running because the battery was bad.

So, my battery is at O'Reilly Auto right now getting the 1 hour plus charge and load test to determine if it is any good. I know for sure it is a 2007 battery, so I'm thinking that it might be a good idea to replace it even if it checks out. Especially since they are on sale for only $20 right now.

If the battery doesn't work, I'm starting to suspect my ignition switch. It is a bit beat up looking and you can pull the key out of it while it is running and it will still run. Am wondering if a faulty ignition switch could be the culprit IF the battery checks out.

Engine is a Kohler cv22. I have downloaded the repair manual for it, but will likely need some guidance as to how to use that manual. If the battery checks out, I guess I will be looking into the procedure for testing the alternator's output.

Thanks to all for any help they might be able to provide.

Follow-Up Postings:

RE: Craftsman 917.257740: trouble starting/keeping running.

If the theory goes that the jump start would also rule out the ignition switch, is there not a possibility that an ignition switch with a short in it could allow the engine to start but then also cause it to shut off while running?

RE: Craftsman 917.257740: trouble starting/keeping running.

The entire scenario....charged battery> mowed nearly the entire yard before engine died> required a jump to restart> ran only a minute or 2 and died again.......sounds like the alternator is not charging. It took as long as it did to discharge the battery the first time because the battery had been charged prior to your using it. It died sooner after the jump because that action did not really recharge the battery...the cranking was actually being accomplished by the donor vehicle battery. As soon as the jumper cables were pulled, the battery began discharging, and with much less charge to lose this time, 2 minutes later the fuel solenoid closes and the engine dies.
If this engine features "Kohler Smart Spark", the Smart Spark module also requires 12VDC to operate, so that too could be adding to the evidence supporting the No Charge condition of the alternator.
The ignition spark on this series of Kohler engines does not use a "battery & coil" to create the spark. The spark is created by a magneto coil next to the flywheel.
I think we need to determine whether the alternator is producing and whether the rectifier/regulator is working too. Do you have a multi-meter or volt/ohmeter?

RE: Craftsman 917.257740: trouble starting/keeping running.

Update. When taking a closer look at wires I found a ground wire terminal on the regulator/rectifier to be so loose that it was nearly falling out of the screw hole. I'm very confident that this explains this entire problem. I suspect this also contributed to the blowing fuse issue that was taking place which I mentioned in the other thread.

New problem has now presented itself. Prior to my having discovered all of this, I was able to get the motor up and running again on the freshly charged battery. I had the engine running and was letting it idle for awhile when I started smelling burning and seeing smoke. Smoke smelled like a burning cable or wire so I shut it down immediately. Once that happened, I have absolutely no power. No headlight-nothing. Smoke was coming out of the screen that covers the flywheel-probably from under the breather assembly. As I have taken it apart, I've discovered that the wires near the SAM and the magneto coil on the same side as the same have this smell. Am in the process of determining if any of these wires is now melted, severed, etc. Checking wires was how I discovered the loose ground terminal on the reg/rect.

Not sure why any of those wires shorting out would cause me to lose ALL power though. Seems it would just prevent me from getting a spark but would still allow the starter to crank and crank the engine without it ever turning over. Acts more like some kind of relay or solenoid is now blown, but the only solenoid I know of on this thing is near the batter and nowhere near where this smoke was coming from.

Any suggestions?

RE: Craftsman 917.257740: trouble starting/keeping running.

Possible that the wiring of the flywheel stator is what I saw/smelled? Just taking a stab in looking through the kohler service manual. Would make sense since these leads go to the reg/rect where the ground was loose and likely arcing/shorting with the vibration of the engine as it was running.

Sound plausible?

RE: Craftsman 917.257740: trouble starting/keeping running.

Disregard any misspelled words. They are intentional to defeat the annoying "key word advertising" Garden Web recently started doing.

***"No headlight, no nothing...."***
Have you checked to see if the fuse has blown? What amp fuse did you use when you repaired the damaged wire (in other thread)?
"Arcing" and "shorting" are 2 very different things. Example: If the reg/rect was loose on its mount, and it depended on the mounting screw to give it a proper ground, it would indeed arc at the screw.........but that would not be a "short" because the current would still be following its intended path. Look the wiring over real good. From what you describe about smoke coming from the screen over the flywheel, I would say something has caused, or created a really bad short that has somehow fed batterry voltage back to the stator windings, and that is not something easily done. I can only think of 2 events that might lead to this. (1) Installing the battery with reversed polarity, even if only long enough to try the starter before discovering the error. (2) Reversing polarity of the jumper cables when jump starting. The possibility here is that reverse polarity can blow a diode in the regulator completely out (open), or it might cause the diode to short and pass current from the battery to the stator wiring. If the stator wirning is back fed from the battery, it tries to become a heating element. Having the correct amp rated main fuse usually prevents this.
You might as well study the manual real close because unless you find a lesser culprit outside the flywheel, you will be removing the flywheel soon. And you are also gonna have to trace out and inspect a bunch of chassis wirning too from what this is turning into.
Now, once again, do you have a multi meter?

RE: Craftsman 917.257740: trouble starting/keeping running.

Sorry for not answering your previous question. I do not personally own a multimeter (mine went bad and hasn't been replaced yet), but I will be borrowing my father-in-law's tomorrow so I will have one then.

As for reverse polarity in the battery terminals and/or jumper cables, that did not occur.

The fuse is not blown, as I had re-removed the fuse holder from the system. Prior to that, I was using a 30 amp fuse. I previously updated that I changed out the holder and it solved the blowing fuse problem. That turned out to only be true for a short time, then the 30A fuse started blowing again. Even stuck a 40A in there to see if it would allow me to sneak by temporarily but it blew the 40A as well. So, I re-removed the fuse holder (that is not a permanent plan-just wanted to get around it temporarily) and that is how things currently are wired in that regard.

So, to be clear, the fuse was not in use when this burning/smoking episode occurred. That is why things got that far without just popping the fuse. Maybe not the smartest move to remove the fuse holder and fuse to get it running, but it was only a short term plan. Hopefully it hasn't backfired on me (no pun intended!).

In the time since my last post, I have checked all of the engine wiring starting at the magneto coils and SAM and traced them back to the solenoid. They are all intact and do not appear to have a single millimeter of cooked or melted insulation on them. If one of them is bad, it is internal and well-hidden at this point.

Was actually preparing to remove the flywheel prior to checking this thread. Looks like I need to find a flywheel strap wrench and a puller.

RE: Craftsman 917.257740: trouble starting/keeping running.

Well, I pulled the flywheel and found the stator burned to hell. You can see pics of it at the link below. The flywheel can be seen at:

Given the completely trashed condition of the stator, and the fact that it has a ground wire that connects directly into the harness that leads to the battery, would this also explain why I have absolutely no power? It seems to me the stator's condition would have broken any connection the negative terminal would have had in the loop.

Here is a link that might be useful: Picture of the stator

RE: Craftsman 917.257740: trouble starting/keeping running.

YIKES!! I also see some physical damage to a couple of the stator coils (at 12 & 1 o'clock in the picture).
Worse than that is what else I think I see.
In the quadrant 6 to 11 o'clock, I see what appear to be 3 (and a fraction) of the flywheel magnets (which are supposed to be firmly attached to the inside of the flywheel).
I suspect that the entire scenario resulted from a single magnet initially breaking loose from the flywheel and crashing into the stator coils, bending them over and shorting them. Further into the scenario, additional magnets got knocked loose. Confirm whether those crescent shaped, dark objects from 6 to 11 o'clock are magnets as I suspect.
As to this being a factor in low power from the engine: Possibly, but it would be hard to say how.
The appearance of rust on the crankshaft and other steel parts suggests that this unit has lived most of its life in a very humid, or even wet, environment.


RE: Craftsman 917.257740: trouble starting/keeping running.

Nice catch mownie, those magnets are definitely not where they below. Never seen that one before.

RE: Craftsman 917.257740: trouble starting/keeping running.

I have had several loose or off magnets. I carefully stick them back on with JB Weld, and they work ok. That stator and flywheel are beyond help, i'd say.

RE: Craftsman 917.257740: trouble starting/keeping running.

Update. Yes, those were the magnets. Several were shredded to hell and so the flywheel was no good, and the stator was likewise toast. I was able to locate replacements, but the flywheel I got turned out to not be a valid replacement. Working on a 2nd replacement flywheel now. When I obtain and install, I'll update again.

Thanks to all for the help thus far!

RE: Craftsman 917.257740: trouble starting/keeping running.

If you are obtaining a used flywheel, you need to check the magnets to make sure none are in the process of coming loose. If you find any loosening, you might want to go ahead and reglue them at this time. Mark them so you can put them back exactly as they are now. Do them one at a time and mark as to which side is up and you will be ok.

RE: Craftsman 917.257740: trouble starting/keeping running.

Got a replacement flywheel that fits and then had the same problem. No power, no nothing when the key was turned. After much tracing of wires and testing switches for continuity, I replaced the ignition switch and it fired right up and ran like a champ.

Thanks to everyone for the help!!!!

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