Knocking Sound??

[LandoCommando214 82]

Today I decided to investigate what my gut was telling me a knock from the motor sounded like. This is a new to me C-160 that I've mostly restored, with the exceptions being no engine rebuild and no tranny rebuild. To me, this "knock" sounds more like a tapping noise at the cylinder head rather than a pinging sound. I've maybe only put two hours on this tractor, and wasn't exactly sure if this is what a K series Kohler just normally sounded like, as this is my first Wheel Horse. Eventually, I just knew something wasn't right because it got louder as the engine warmed. I thought this could be spark knock, so I decided to order a new plug, set of points, condenser and wire. These parts should arrive on 6/1, so today I thought i'd take a minute to check my valve clearances and rule out any slop that may be causing this sound; here's where things get interesting...

 

As I pulled the valve cover assembly off, I noticed the center stud was loose, so I had to grip it with a pair of channel locks to remove the nuts. Ultimately, I found that the breather assembly had been taken off before by the previous owner and installed incorrectly, with the filter retaining plate up against the valve springs (item 4 below was assembled first, right up against the springs):

 

 

Here's what the plate looks like. 

 

 

 

This was pretty frustrating to find. I thoroughly cleaned everything and reassembled to see if this plate was causing the sound I've been hearing. Unfortunately, the sound is still present. Still gets louder when the engine is warm. This engine doesn't burn a drop of oil, so i'm hoping the bore and rings are OK. Does anyone know what my next steps should be? Could this be an unrelated issue, suggesting the new ignition parts may still fix the noise? Do I have excessive wear between my crank and rod? Sloppy valve guides?

I'm afraid this engine could be damaged badly.

 

Here's a link to a video of the engine running when warm. How does this sound in comparison to other K341's that you've all heard? Does it sound like something specifically?

 

https://photos.app.goo.gl/NHvW65G3sTFCEnWR6

 

 

Valve clearances checked out fine btw..

[953 nut 51,655]

My first thought is that the "Balance Gears" (AKA Grenade Gears) are about ready to cause major damage. Read this information and you will see what I am talking about.

 

 

[pacer 3,159]

Yep, "grenade gears" was my first thought too, and and "tapping sound" usually better describes it.

 

While you are in there you should go ahead and get your crank and cylinder checked  -- and if good go ahead and get one of the rebuild kits, you gonna need a bunch of gaskets anyway and I have had good luck with the import kits, very inexpensive. Two rebuilds on K361, the last one was during a grenade gear check -- which I removed!

[LandoCommando214 82]

Thanks guys. That's probably the only way I'll be able to remove all of the metal shavings from the engine anyway, and I'm sure they're everywhere. I don't know how long the previous owner had run the engine like this. 

 

So this engine should run fairly quiet then? Much quieter than what you can hear in the video? On a scale of 1 to 10, how "sick" does this motor sound to you guys? 

[LandoCommando214 82]

**UPDATE**

 

I've corrected the valve breather assembly so it no longer rubs on the springs/keepers. I've flushed out the crank case and oil pan the best I could and changed out the oil several times, until I was no longer seeing metal shavings/old oil coming out of the drain plug. I've replaced the points, condenser, plug, and plug wire. Gaped the points a little tighter than the manual suggests, closer to 017" and the top end noise seemed to quiet down a TON. Cut with it for about an hour last night and checked the oil again; super clean and no metal shavings. Noise is not gone, but it's much better. Could it have been timing???

 

Unrelated: 

I was able to contact the previous owner and ask about a history on this engine. He states it's only got one season on it after a rebuild.