Kohler CH 20

[John2189 536]

Ok. I put air pressure into the cylinders cold. Both cylinders air is passing out the intake. It does have hydraulic lifters,could that be why?

I did a compression test. One cylinder was 145  and other was 110. Again it was cold. 
this motor only has 900 hours on it. It was a mowing tractor for mabey 5 years then for 20 years it only plowed snow, so it sat unused for years. 
Oh and it has a lot of blowby in the crankcase, so much that the vacuum fuel pump would not work, so I put a valve cover pump on it. 
is it worn out?

Edited May 6 by John2189

[oliver2-44 10,679]

Yes, i've read that the hydraulic lifters can leak down and effect a compression test.

I've also read manufacturers literature recommending the engine be at operating temperature for both of these test.

 

As to is it wore out?  Redo the test hot.

Maybe it just needs a de-carbon and valve job.

[JoeM 8,280]

5 hours ago, John2189 said:

One cylinder was 145  and other was 110

If you had a collapsed lifter, these would be really bad. I consider good compression on a ch engine to be above 150.

that blow by is telling the story. 

900 hours mean nothing if good routine maintenance was not preformed. 

the best test is a leak down on a warmed up engine. 

by what you are saying not sounding too good. 

[John2189 536]

51 minutes ago, JoeM said:

If you had a collapsed lifter, these would be really bad. I consider good compression on a ch engine to be above 150.

that blow by is telling the story. 

900 hours mean nothing if good routine maintenance was not preformed. 

the best test is a leak down on a warmed up engine. 

by what you are saying not sounding too good. 

I’ll check compression and leak down when warm tomorrow. I got a feeling it won’t change much 

[Wild Bill 633 877]

Remove the breather cover to check and see if the breather reed valve is broken.

Edited May 7 by Wild Bill 633

[John2189 536]

4 hours ago, Wild Bill 633 said:

Remove the breather cover to check and see if the breather reed valve is broken.

its ok. 
 

[RED-Z06 2,567]

Early command Twins could have head gasket problems, your blowby could be related to this, as well as the low number.

[Fordiesel69 271]

Kohler command engines are really good but they can blow head gaskets.  Tear the heads off and spend some time doing a valve job and reseal.  

[John2189 536]

3 hours ago, Fordiesel69 said:

Kohler command engines are really good but they can blow head gaskets.  Tear the heads off and spend some time doing a valve job and reseal.  

That is what I’m planning on doing.