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Kohler Command 25Hp Problem


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#1 Auburn David OFFLINE  

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Posted September 25, 2014 - 10:10 AM

Hello all!!!

 

I have a KOHLER Command 25hp that last year when I went to turn it off it backfired and seems to have bent the valves on one of the heads.I am pretty sure the head will have to be replaced because the valves are stuck in it and will only move if forced.

 My question is...WHY DID THIS HAPPEN?before I spend money and time to fix this engine I would like to know if anyone else has had similar problems,and if something else needs to be looked at.

 This engine has very little use on it and was bought new(on a Craftsmen GT5000) a few years ago.

 

Also if anyone has any used parts for this engine I had rather buy from you folks than Ebay if I can..but I am on a budget for sure.

 

Thank you all and I love this group!

 

PS..engine still runs good on the one cyl.


Edited by Auburn, September 25, 2014 - 10:28 AM.


#2 Talntedmrgreen OFFLINE  

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Posted September 25, 2014 - 10:50 AM

Sounds like it was shutdown at low rpm. Backfire is the result of this on KT's, Magnum's and Command's that have a shutdown solenoid. The book calls for throttle position between half and full throttle....this is counterintuitive for most folks, especially if you learned from Dad or Grandad.

Usually the result is a blown seal or headgasket.
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#3 Auburn David OFFLINE  

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Posted September 25, 2014 - 11:02 AM

Sounds like it was shutdown at low rpm. Backfire is the result of this on KT's, Magnum's and Command's that have a shutdown solenoid. The book calls for throttle position between half and full throttle....this is counterintuitive for most folks, especially if you learned from Dad or Grandad.

Usually the result is a blown seal or headgasket.

Yea,I always throttle them down for shutdown..think replacing the head will fix this engine?or will there be more damage?



#4 skyrydr2 ONLINE  

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Posted September 25, 2014 - 11:13 AM

They are a cake walk to work on . find a valve and replace it and head gasket and you should be good to go. We pound the living dickens out of the Kohler's we have and they just keep on taking it.
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#5 Auburn David OFFLINE  

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Posted September 25, 2014 - 11:20 AM

They are a cake walk to work on . find a valve and replace it and head gasket and you should be good to go. We pound the living dickens out of the Kohler's we have and they just keep on taking it.

so you dont think the valve guide is damaged?



#6 Auburn David OFFLINE  

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Posted September 25, 2014 - 11:21 AM

I will also have to have 2 new pushrods,the ones in it are bent pretty bad.



#7 MH81 ONLINE  

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Posted September 25, 2014 - 11:48 AM

Sounds like it was shutdown at low rpm. Backfire is the result of this on KT's, Magnum's and Command's that have a shutdown solenoid. The book calls for throttle position between half and full throttle....this is counterintuitive for most folks, especially if you learned from Dad or Grandad.
Usually the result is a blown seal or headgasket.


Every blessed time I do it the 'right' way, I get a heart palpitation courtesy of a backfire. Rarely to never when I idle them down. 25 hp courage, 26 magnum, and 26 elite in the mix.
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#8 glgrumpy OFFLINE  

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Posted September 25, 2014 - 12:26 PM

Have 23 vert shaft on Deere that always pops when shutting down fast. I now let it run slower when putting away after mowing, and even let it idle a minute or so before shut-down. Sometimes still get "Poof" but not hard that way. I have even gotten off tractor a few times and then the "Poof" comes late, kinda odd. If I shut down hot and fast, it will bang hard sometimes, try not to let it do that now.


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#9 Auburn David OFFLINE  

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Posted September 25, 2014 - 12:33 PM

Have 23 vert shaft on Deere that always pops when shutting down fast. I now let it run slower when putting away after mowing, and even let it idle a minute or so before shut-down. Sometimes still get "Poof" but not hard that way. I have even gotten off tractor a few times and then the "Poof" comes late, kinda odd. If I shut down hot and fast, it will bang hard sometimes, try not to let it do that now.

Sure made a mess of the one I have..



#10 skyrydr2 ONLINE  

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Posted September 25, 2014 - 01:18 PM

Take the head off and check to see if the rod may be bent? Or worse broken? It shouldn'trun very well on one cylinder if the intake valve is stuck open??

#11 Auburn David OFFLINE  

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Posted September 25, 2014 - 01:22 PM

Take the head off and check to see if the rod may be bent? Or worse broken? It shouldn'trun very well on one cylinder if the intake valve is stuck open??

dont hear any knocks..runs pretty good on one cyl actually.



#12 Talntedmrgreen OFFLINE  

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Posted September 26, 2014 - 08:01 AM

Every blessed time I do it the 'right' way, I get a heart palpitation courtesy of a backfire. Rarely to never when I idle them down. 25 hp courage, 26 magnum, and 26 elite in the mix.

 

 

I'm unfamiliar with these engines.  I know there are differences in the shutdown procedure between some.  The 26 Command, for example, does call for a low idle shutdown.  I think the input need to remain with the 25 hp Command vs other models, for accurate info. 

 

My experience with my only Magnum, and all Commands I've had is just the opposite.  My KT's have been mixed.  I could get rich betting that each of my CH25's will backfire if idled down before I flip the key off.  I leave my RPM right at 2250 on the tach, and have never once had a backfire since changing my method.  Took some getting used to...I just can't bring myself to shutting down from a higher speed than that, and haven't had to try.  

I think the Kohler tech's would provide plenty of backup to the factory's recommendation, but each engine will act differently.  There are quite a few guys out there with this very problem, who either fault the engine, or simply change their tune about the shutdown process and go on with life.  If you have the solenoid, and it backfires at the recommended RPM shutdown, then by all means, do what you need to, to prevent it.  But obviously, that isn't the case here.

 

It's amazing how folks cannot change their school of thought, regardless of the consequences and fact behind it.  I'm a terrible example...I've been running my engines by the book for only about 2 years now, and while it is clearly correct, I still cringe every single time.  Every time.  I always feel like Grandpa is shaking his head, and I know for a fact that my old man just would NOT leave that idle up no matter what.  But, Kohler built them, and Kohler says to leave the idle up, so I do, and I haven't so much as had a hiccup in 2000hrs of combined use on this model engine.


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