Question about Kohler k181 engine

[mgrant]

My original Cub Cadet has a 1971 K181 replacement engine that was running perfectly until yesterday. Just started to loose power then died. Sounded like compression issue before it died so I pulled the head off hoping to see something. Piston and cylinder look ok nothing major seen. I did observe something funny with the intake valve seem to open slightly after compression cycle. I don’t think this is correct and before I tear everything apart I was wondering if anyone has had issues with the valve springs in this engine or is there a common component failure that happens with this engine? Thanks in advance for any ideas.
Marty

 

[rbedell]

The valve springs are not normally a problem issue. Carbon deposits on the valve stem are more common.

 

[mgrant]

Thanks for the input, have you ever seen a head gasket fail to cause loss of compression? Still looking and hoping for an easy fix.

 

[dmerkle]

Sounds like your IH Cub Cadet has a cam with a compression release built into it. That would explain the reason for the intake valve popping up some.
Can you provide a spec number off the engine tag?

 

[mgrant]

Oh wow did not even know that existed in these engines attached is a picture of the engine tag. The spec number is 30452D. Thanks for any info.

 

[dmerkle]

By the looks of an Kohler parts lookup it is possible to have a cam with compression release or a non compression release cam.

According to Kohler Service manual your engine was made in 1978 if I read it right.

Can you post a picture of the head gasket( both sides) ?

 

[mgrant]

I need to correct myself it is actually the exhaust valve that cracks open which now makes sense to me ( I never studied the assembly drawings I did not know that these engines came with compression release). I am going to just replace the head gasket I try for the easy fix without removing the engine from the tractor. The old gasket separated into sections when I removed it and the head came off easily so going to give it a try before digging deeper. I will know in a few days when I get gasket delivered hopefully I can get this tractor operational since I am knee deep in leaves now.

 

[eweiss]

Be sure you clean all old gasket material off both the block and head. Use a good torque wrench in across pattern for even torque

 

[dkirk]

After torquing head bolts, run engine at fast idle for 15 - 20 minutes, no load. Shut down and let engine cool back to ambient temperature. Retorque head bolts. You'll probably find that torque values have relaxed some - this is normal. This second procedure is important and will prevent head gasket failure in the future.

 

[mgonitzke]

While you have the head off, check the valve lash and condition of the valves.

 

[PACub100]

Another thing, I'd want to check the head for flatness prior to re-installation. Isavetractors has a youtube video on checking and sanding it...

 

[mgrant]

Update on repair and things I learned, just when you think you know what you are doing…..long story if you are interested.
Well my original is running after I changed the head gasket even though it looked ok after I took it apart. As part of my diagnosis I removed all drive belts leaving only the generator connected. I verified that I had spark with the plug out and grounded to the engine. Tried to start it many times until I killed the battery. At the point I convinced myself it was the head gasket or maybe a piston or ring problem or bad cylinder because turning over by hand seemed to have little or no compression. Not until I pulled the head did I learn that these engines had a compression release. So must be head gasket right… Assembled it all back together and yes started right up with no drive belts connected. Yea.. but wait next I connected up the drive belts and you guessed it won’t start. So ok disconnected the mower deck and yes now it starts. So while wearing my hearing protection what sounded like a change in engine noise was really a bearing freezing up on the mule. So why did it not start after I tested it with the drive belts disconnected? Could it have been the dreaded double failure? I guess I will never know. But at least I learned about compression release and enjoyment from keeping it running after all its 62 years old and how many things last that long. Video attached just for fun.

 

[jkoenig]

Glad to hear it runs! Good job.

 

[Mike Canfield]

How is your tractor doing now? Still working for you?