More problems on the 425 Kohler CH25

   / More problems on the 425 Kohler CH25
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#91  
Hmmmmm…sure is! 🤔
 
   / More problems on the 425 Kohler CH25 #92  
Does the dent extend down to the first piston ring?
Also it likely has bulged up material at the head sealing surface that will need to be taken down before a head gasket will seal properly. I would check with a straightedge or precision scale
 
   / More problems on the 425 Kohler CH25
  • Thread Starter
#93  
Does the dent extend down to the first piston ring?
Also it likely has bulged up material at the head sealing surface that will need to be taken down before a head gasket will seal properly. I would check with a straightedge or precision scale
It’s hard to see, but I wouldn’t call it a dent (a depression from the top surface down towards the bottom)—it’s more like the side of the bore is missing some surface material…make sense? Sorry, I should have lowered the piston down to examine closer…I’ll do that shortly and repost…
 
   / More problems on the 425 Kohler CH25 #94  
I hate to armchair quarterback, but for an engine, that looks like a big dent outwards and upwards. Have you measured how much the deviations are?

All the best,

Peter
 
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   / More problems on the 425 Kohler CH25
  • Thread Starter
#95  
I hate to arm chair quarterback, but for an engine, that looks like a big dent outwards and upwards. Have you measured how much the deviations are?

All the best,

Peter
I hear you! 😊 It sure alarms me too, but I haven’t gotten back to it this evening (had to make long distance run with wife for groceries and meds, and it’s been pouring the rain…arrrrggggg) Also, it appeared to me that the surface area of the impression is smooth—I would have thought it would have some kind of roughness to it…maybe constant heat had something to do with it, since the gasket was leaking in that area…?
As soon as I can, I’ll investigate closer…
 
   / More problems on the 425 Kohler CH25 #96  
I know you want to see if you can get it going. I'm pulling for you.

I think I would replace both heads and be done with it.

But that's coming from a guy who's engine has been sitting next to his PT for several months doing n-o-t-h-i-n-g! :ROFLMAO:
 
   / More problems on the 425 Kohler CH25
  • Thread Starter
#97  
I know you want to see if you can get it going. I'm pulling for you.

I think I would replace both heads and be done with it.

But that's coming from a guy who's engine has been sitting next to his PT for several months doing n-o-t-h-i-n-g! :ROFLMAO:
LOL I probably didn’t detail it correctly—the impression is in the block part. I think the heads are ok after a little prep work, and all new parts to boot…but…
Now…I’ve come to the point of it being apart so long I kinda dread starting back on it. (Seems to have gotten worse with age😯) I have to get my mind fully involved in it again with no other distractions. And my mind keeps getting excited at new fix prospects, so I tend to be all over the place. I think they call it “too many irons in the fire”…LOL
 
   / More problems on the 425 Kohler CH25 #98  
LOL I probably didn’t detail it correctly—the impression is in the block part. I think the heads are ok after a little prep work, and all new parts to boot…but…
Now…I’ve come to the point of it being apart so long I kinda dread starting back on it. (Seems to have gotten worse with age😯) I have to get my mind fully involved in it again with no other distractions. And my mind keeps getting excited at new fix prospects, so I tend to be all over the place. I think they call it “too many irons in the fire”…LOL
I'm sorry, I knew you meant the block not the head. I'd replace it.
 
   / More problems on the 425 Kohler CH25
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#99  
I'm sorry, I knew you meant the block not the head. I'd replace it.
Oops—my fault! I didn’t think it through enough, and when you mentioned “jug” I remember that from a small Honda cycle motor I was working on a couple years ago…
So that “jug” separates from the block as well, enabling it to be replaced? I think I need to study a little more—I thought I had it all figured out! LOL
I’ll be lucky if I ever get this thing running again…😜
 
   / More problems on the 425 Kohler CH25
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#100  
I'm sorry, I knew you meant the block not the head. I'd replace it.
When I first saw it, I had been considering…(keep in mind I have no real “skill” but have always relied on trial-and-effort, printed materials, and plain old ‘I think it works like this—what if I try this?’”😆)
…that since that depression opened up that space just a little more that it would be contained by the gasket and the head above it. Maybe not enough to hurt the performance too bad—after all it’s been running fine for about the last three years. I know that’s not the way it should be looked at and everything should be replaced, but sometimes I have to get there the “hard way”…LOL
 
 
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