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Discussion Starter #1
I'm mowing the lawn, a bad noise, the Gravely gives out. When I try to start the engine, the alternator engages the flywheel, but it doesn't start. And it sounds to me like the flywheel is not engaging the engine, if that makes sense. Also, it will now attempt to start even though it's in gear, which it never did before. Any help would be greatly appreciated.
 

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Discussion Starter #3
Exactly. It does seem that way. If I spin it with my hand it seems to spin freely. It's like it's not attached to the crankshaft (I'm assuming that it should, but I could be wrong). The engine doesn't seem to be making any noise when I try to start it, if that makes sense.
 

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Discussion Starter #5
Well that's not exactly great news, but the more I think about it the more I realize that you're probably correct. Are you familiar enough with these engines that you know if I can get to this (to replace the rod) by simply taking off the flywheel? I say simply, but the truth is, I tried to take the flywheel off yesterday but couldn't get it off. Thanks for your help, by the way.
 

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Nope, engine off.

But that's really easy on these things. After you disconnect the electrical and fuel and stuff, there's 4 bolts which hold the engine on the back of the tranny. Pull those, and it comes right off. Make sure you have a floor jack under it while doing that operation.

There's lots of manuals on how to do that kind of disassembly, as well as getting into the engine, at www.oldgravelys.net
 

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Discussion Starter #7
What would you think we're looking at here, parts and labor? I'm thinking probably more than I'm willing to spend on it at this point.
 

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Ron C knows some one that has rebuilt motors he could put you in contact with him and you could get a price.

Be carefull not to drop the key that is under the gear when you slide out the motor.
 

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Isn't this a 12hp Kohler? Can't he drop the oil pan to get top the rod bolts and pull the head, run a ridge reamer and pull the piston up with the motor in place? The he could see what really happened that there was no other damage.
 

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Discussion Starter #10
I am now toying with the idea of trying to fix it myself, but I'm no mechanic. I just hate to scrap the thing. It's in good shape other than this thrown rod.
 

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Isn't this a 12hp Kohler? Can't he drop the oil pan to get top the rod bolts and pull the head, run a ridge reamer and pull the piston up with the motor in place? The he could see what really happened that there was no other damage.
Well, actually, maybe yes. If you can get the pan off without removing the engine, then it ought to be doable.

I'm pretty sure the book sez you're supposed to pull off the side case and go in that way, but there's more than one way to repair a rod. I've changed out rods and pistons on flatheads without pulling the engine, so why not here :-?

Troutman, I recommend you give it a go. Whether or not you pull the engine off, these machines are pretty straightforward and easy to work on. If you sell it, it's gonna be for parts anyhow, so who cares how taken apart it is?

The thing that I wonder about is whether there's anything else that's awry in there. It may be that the only thing wrong is the rod, clean the crankpin, pop in a new rod, and you're good to go. But if it was insufficient lubrication, there could be other things in there showing inordinate wear as well. The only way to tell is to get into it.

Have fun with it, and please post lots of pix!
 

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If you just need the rod, I see replacements on ebay for ~30 bucks new, ~10 bucks used. I'm pretty sure you can order all that stuff from kohler, probably other aftermarket places too.

Depending on what happened, you might need just the rod, possibly crank and piston too. If the lubrication failed, it might have scored up the crankpin pretty good. That would call for either replacing the crank or having it reground. If you grind it, you'll need a rod that's machined undersized to fit.

Again depending on what happened, you might want to hone the cyl, and possibly replace the piston. Do the rings, even if you don't replace the piston. If the cylinder is scored up, you'll want to bore it to a size over, then you'll require a new piston and rings anyhow.

Don't forget to buy fresh gaskets for whatever you open up.

First order of business, open it up and disassemble enough of the innards to get a handle on what parts you need.

:wwp:
 

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Discussion Starter #14
Seems like good advice to me. I'll decide in the next day or so which way I'm going to go on this thing, and your advice will weigh heavily into that decision. I can get $150 for it at a local mower shop; I might better just take that offer, much as I hate to see it sitting around for parts.
 

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I hate to see it go for parts too, much rather hear about it running. Take the head off and see if the piston goes up and down when you turn the crank. If the piston doesn't move drain the oil and take the pan off, it's on with 4 bolts, it's easy. See what it looks like and show us some pictures. I always say you can't break what is already broken.
 

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Discussion Starter #16 (Edited)
al b - I will probably spend some time on it. That being said, if the piston goes up and down when I turn the crank, that would mean I haven't thrown a rod, which I'm pretty sure I did? Just saying....
 

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Discussion Starter #17
OK guys I got the piston out, as well as the broken pieces of the rod. It looks to me like the cylinder is fine. When I turn the crank the valves go up and down like they're supposed to. Just a couple of things and I hope I'll be ready to put in a new piston and rod, new gaskets, and put her back together. Now, the troubling points. When I took off the oil pan, along with the broken rod parts was another broken piece in the bottom of the pan that I don't think goes to the rod. It looks almost like a knife blade but thicker. It's narrower on one end than the other. It's very light, I think aluminum. Also, it appears broken, and I don't find the other piece anywhere. HELP!
 

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From your description it sounds like its the "dipper" on the buttom of the rod. The single cylinder Kohler engins had an extention to the bottom of the rod to help splash the oil around.

Peter
 

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Agreed. You can see it in pix of those rods, a flat thing sticking off the bottom of the rod end cap. You should find a broken spot in the middle of your cap which matches the thick end of the piece you found.

How does the bearing surface look?

It's likely that your rod is stock size (ie, not undersized) but it's worth miking the crank anyway, to be sure.
 

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Discussion Starter #20
Well, well, well... now THAT makes sense, because I was under there looking and I couldn't see how much oil would get up into the engine, based on where the oil level should be. That is GREAT news, as I was worried about that little bugger. There was a small burr on the crank pin, probably happened when the rod broke, but I was able to carefully file it off. I think it'll be OK. Sounds like I'm ready to put this thing back together. I cleaned the carbon around the valves, but they seem to be seating nicely. I know I should probably do the whole works since I've got it apart, but I didn't have to remove the engine, and don't really want to. Making it as painless as I can.
 
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