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Discussion Starter · #1 ·
How would one best diagnose a rod knock without tearing down the engine? I first thought I had a valve tap, but the valves appear to be correct. I want to get an idea of what needs to be done before I tear into the motor. Thanks
 

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Tractor Fixin
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Have you tried a mechanics stethoscope? They come in various models. Oh, I dont know, but it may help. The most common variety is something like a 16" phillips screwdriver.
 

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Discussion Starter · #3 ·
I do have a stethoscope, but I'm not quite sure what to listen for. I guess if I hear some knocking by the crank area then that would indicate something.

I did turn the motor over by hand and at TDC I can rock the crank back and forth and hear a knock, but at just about any other position I don't hear it.
 

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10K and Climbin!
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Take some time and diagnose the thing well before diving into a rebuild.. Oil condition or comsumption(piston blow-by), compression (If Comp/release- spin backwards).. How many hours on the engine? The sevarity of the knock matters too. I've seen wrist pins knocking in the past and the thing keeps on running great.. But since you noticed trouble tearing into it could save you a catastrophic breakdown.. Does that engine (Kohler?)have the dreaded balance gears? They could be going south.. It's hard to diagnose from my chair here.. Just my .02! :goodl:
 

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Discussion Starter · #5 ·
I cleaned up the tractor and just got it running so I have no history on it. It starts up immediately, runs like a champ and doesn't smoke. Compression feels good (need to check with the guage). I have to look into the balance gear thing, I'm not sure. It's a KT17.
I don't expect anyone to diagnose from the internet, jsut looking for some things to check before I decide what to do.
I appreciate the help!
 

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I assume that the engine is a 16hp Kohler as the only tractor you have listed is that grand old Wheel Horse.

If it were me, I would pull that engine and tear it down now, before something bad happens. Those engines are indestructible if properly cared for. That being said, everything wears and in different places, according to the manner in which we use them. Might be a rod bearing, piston slap, worn rings, wrist pin, or maybe the valves. In any event, it will need to be fixed. Even if it is a valve, to properly fix it will necessitate pulling the engine and tearing it down.

Do it now and you may only have a small problem to fix. Wait and keep running to diagnose the problem may cause complete failure of a vital part and further damage the engine.

Nick
 

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I had a similar problem with a 13hp Tec. I ran it just one more time and threw the rod cap out the side of the case.

I say better to err on the side of caution, my tec. not a huge loss, your Kohler would be a bigger loss.

Just my $.02.
 

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You could have a busted piston (at the skirt), but regardless, the Kohler is too fine a product to damage or destroy by delay in repair, especially if the engine is of the original type to the mower.
 

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Discussion Starter · #9 ·
Pulled the motor and then pulled the cylinder jugs. Found out that the knock is some slop between the cam gear and the drive gear. There doesn't seem to be any end play of the cam and the teeth don't appear to have exessive wear. Weird

Any KT17 experts have any opinions?
 

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I am not sure that would cause a knocking sound. Of course I am no expert by any means.
 

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All Fired Up
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Measure that slop and let us know how much. Something has to be worn severely for that to cause a knock. Check crank and cam bearings and bushing.
 
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