Low Hour Kohler CH20 Burning Oil

[Morkai]

The CH20 in my GT2544 starting burning oil on the right side and smoking a lot. (see pic of right plug) It has less than 200 hours on it.

I don't have a leak down gauge, so I haven't been able to do that yet. I checked vacuum at the dipstick tube and it was fluctuating around 1-2".
I heard about the reed valve problem on the twins causing them to suck in oil and burn it, but I would think that would be in both cylinders. Is it possible it blew the head gasket? I sure hope I don't have to rebuild this thing with under 200hrs on it.

 

[Billrog]

Is the air filter clean they'll heat up and smoke it it's plugged up?

 

[Bob_Bainbridge]

My 2004 3235 with Kohler Command 25 had the same problem. It blew a head gasket with 300 hours and I found the head bolts were barely tight. I replaced gaskets, torqued the bolts, ran it up to operating temperature and retorqued them. I had no further head gasket problems but the right cylinder started fouling the plug with burnt oil and had to be cleaned monthly. I never did a compression check but power and sound seemed normal. At 550 hours the front seal went and would leak out 1 quart of oil during a 2-hour mow of an acre. The dealer said it would cost $500 to replace the seal, requiring the engine to be pulled. With the oil leak, the bad cylinder and then the vacuum PTO actuator went bad, I decided to trade it in on a 2015 XT3-GSX.

Bob B.

 

[RandyT]

Lets start with a compression check on both cylinders. You can do compression check on the command because there is no compression release. If you don't own a gauge you can get free rental at most auto parts stores. The 1-2" of vacuum is low but is that with a mercury gauge or water gauge. Small engine manufacturers use water vacuum, not mercury so I don't know what your actually readings are.

 

[Morkai]

I am leaning towards head gasket or valve seal. I was afraid the excessive dirt had gotten into it and wore the rings, but it would probably be bad on both sides.

I do have a compression gauge, I read something about the ACR and figured that was a no go. I remember it looking pretty good. I'll get some readings on both cylinders today. Is it better to do it with both plugs out or one at a time?

Vacuum is in inches of mercury. I was mainly checking to see if it had a vacuum or pressure. My finger test had suggested vacuum. I wasn't much it was bouncing back and forth with the pulses between 0-2" mostly in the 1-2 range. I do have a 3225 with a CH22 I can take a vacuum reading on to compare.

 

[RandyT]

Perform the compression test with both plugs out and the Command engine doesn't have ACR.

 

[Morkai]

BTW, it's a CH20S spec 64638

I got a max reading of 170psi on both cylinders cold. I did see fresh oil on the right plug and even the adapter after running the comp test. It looks like the breather tube has some oil inside it too. So maybe it is sucking oil up through the breather. Is there any reason why there would be more oil going to the right cyl?

 

[RandyT]

Kohler has readings for a warm engine which normally create lower readings than cold engine. I suspect you have a head gasket issue on that cylinder.

 

[Morkai]

Kohler has readings for a warm engine which normally create lower readings than cold engine. I suspect you have a head gasket issue on that cylinder.

I am inclined to believe you. I pulled the breather cover and the reed looks ok, but there is oil all in there the filter looks soaked and there appeared to be oil in the breather hose. I'll bet it blew the gasket at the oil drain and is blowing back through the crankcase, but that cyl sucks a lot more oil back in on the intake stroke than both are getting back through the carb. I guess there's only one way to find out, pull the head. It's head 1, on the right side.

When I lookup the head gasket I get p/n KH-24-841-01-S. That looks like the oem gasket, isn't there supposed to be an updated version? Or is that only for the 25 and above?

 

[RandyT]

That was for the larger engines. the head gasket issue was on the 25 hp engines and didn't effect the smaller engines.