Kohler CV15S - Rod Knocking or Something Else?

[Bavanrauser]

Silverleaf,
MY 2002 JD LT150 Kohler CV15S just came up with this same problem over the weekend. Started and continues to make the exact same sound as you provided in the uploaded video. Began as I was finishing up a very short run. Did you ever come to a find diagnosis of the underlying problem? What was the remedy?The machine has been perfect until this. All maintenance was carried out on schedule.

I look forward to your reply.
Thanks.

 

[Silverleaf]

Silverleaf,
MY 2002 JD LT150 Kohler CV15S just came up with this same problem over the weekend. Started and continues to make the exact same sound as you provided in the uploaded video. Began as I was finishing up a very short run. Did you ever come to a find diagnosis of the underlying problem? What was the remedy?The machine has been perfect until this. All maintenance was carried out on schedule.

I look forward to your reply.
Thanks.

It was exactly as Fish said. A throttle plate set screw came loose and got sucked into the intake. I couldn't remove it without a great deal of work because I rounded off a head bolt when I got in a hurry taking it apart. Long story short, I replaced the screw, and have been using it as-is ever since. I believe the screw has been pulverized by now. Everything seems fine, and it has gotten a lot quieter. I mow close to 1.5 acres with it, and its been fine so far.

 

[Fish]

Yeah, that little screw is likely pounded deep into the piston, or else blew out the exhaust. Thanks for getting back with the results, these guys here don't believe me most of the time..........

 

[Mr. P]

HI, I'm new to the forum. I wanted to share something that happened to my mower last week. Same as others have posted on this, finally discovered that one of the throttle plate screws got sucked into the engine, made a terrible knocking noise. Was quite convinced it wasn't a rod due to the pitch, but my local John Deere dealer thought it was, as I had recorded a short clip for him to hear. An online search brought me to this forum and the prospect of the throttle plate screw seemed very likely, and after verifying that a screw was missing in the throttle plate, in I went. Sure enough, the screw was embedded into the head and a dimple was formed in the piston. So a few hours later with a new head gasket, exhaust gasket, new throttle plate screw (with #609 LocTite, on both!) and oil change it is up and running smoothly again. Thanks for all the great information that is posted here, I will keep an eye on this site regularly!:smile:

 

[bertsmobile1]

Yeah, that little screw is likely pounded deep into the piston, or else blew out the exhaust. Thanks for getting back with the results, these guys here don't believe me most of the time..........

Seen it more than once, just as you describe.
Even seen one that had gone into the piston thread side down and the customer thought it was supposed to be there.

 

[hackler01]

Seen it more than once, just as you describe.
Even seen one that had gone into the piston thread side down and the customer thought it was supposed to be there.

HI Guys - Im new here as well. Like Silverleaf, I own a 2002 JD LT150 Kohler CV15S. Great machine, very well cared for, but it suddenly developed a bad knock last time I used it. Sounded like a push rod problem, but I Googled around and watched several "Taryl's" videos on youtube. Taryl mentioned the screw issue in one vid, and I learned more about it here as well. Long story short... I have the same exact issue! When I read about the issue here and then saw that one screw was missing on my throttle plate, I pulled the valve cover and then the head, and found the screw which has beat up the piston rather badly, lodged into the cylinder head. (see pics enclosed). I plan on cleaning that head and piston up, replacing the gaskets, etc, and Im hopeful that the Kohler comes back to life. "Mr. P" and others - thanks so much for your post and pics, they really helped me diagnose this strange issue.

 

[Scrubcadet10]

Just hope your piston rings aren't pinched... It may smoke quite abit. Only one way to find out.. Unless you remove the piston.

 

[Fish]

I had one real old tecumseh once suck in a screw while mowing. The rod just disintegrated, everything else was fine.
Put in a new rod, cleaned up everything, replaced/loctited the carb screw, and the thing ran like new.