20 hp Kohler command?

[Geo-TH,In]

My terramite has a 20 HP Kohler command with hydraulic lifters, over 2000+ hours. For some reason after it sits for weeks it only starts on the right cylinder for about 10 seconds before the left cylinder kicks in . Both sparks are clean so i discount a spark issue, There is only one carb, so I discount a fuel issue because it runs fine after a few seconds. I'm guessing a valve issue. possibly a rusty valve stem or a hydraulic lifter problem. Do you have a 21 year old kohler command with a similar problem?
When I have time and it warms up. i will remove the valve cover and observe the valves to see if one valve Is stuck open. MY Jubilee exhaust valve stuck open. I sprayed wd40 on the valve stem and inside the cylinder and put the pushrod back in place. After running on 3 cylinders for about 10 seconds the valve broke loose and ran fine.

 

[MarkB_MI]

George, it stands to reason that since it's a two-banger you'll have at least one valve open any time you shut it down. A little snake oil in the form of Marvel Mystery Oil probably wouldn't hurt. Put a healthy dose of MMO in the gas tank the next time you use it.

There's a product primarily for outboard motors called "fogging oil". You can spray it in the intake if you're not going to be using the machine for a while.

 

[Duner Wi]

I vote for giving MMO a shot. Cheap easy and it works if Indeed a sticking valve due to certain conditions.

 

[Geo-TH,In]

I vote for giving MMO a shot. Cheap easy .and it works if Indeed a sticking valve due to certain conditions.

I'm thinking maybe I have a hydraulic lifter problem and will buy snake oil for hydraulic lifter. I know very little about hydraulic lifters. The motor holds 2 quarts of oil. I may the drain oil before adding snake oil or MMO

 

[MarkB_MI]

I'm thinking maybe I have a hydraulic lifter problem and will buy snake oil for hydraulic lifter. I know very little about hydraulic lifters. The motor holds 2 quarts of oil. I may the drain oil before adding snake oil or MMO

George, a stuck lifter shouldn't keep the valve from closing. It'll rattle a bit but it should otherwise run OK.

 

[Geo-TH,In]

George, a stuck lifter shouldn't keep the valve from closing. It'll rattle a bit but it should otherwise run OK.

Them I have a sticking valve stem or carbon up valve. After I start it no problem for the rest of the day. Can you explain that? I startef it yesterday. I'll see what happens today. I need to move it in a few hours.

 

[MarkB_MI]

Them I have a sticking valve stem or carbon up valve. After I start it no problem for the rest of the day. Can you explain that? I startef it yesterday. I'll see what happens today. I need to move it in a few hours.

Yes, I agree it's likely a sticking valve.

 

[Geo-TH,In]

What can I put in the gas to clean carboned up valve stems.

 

[Absent Minded Farmer]

What can I put in the gas to clean carboned up valve stems.

Just pull them & clean them. The heads come off easy & the gasket set to cover everything is about $45.

Also, I have no idea what causes the cold cylinder start. It seems to be a thing with the CH series. Ours has been doing it from at least 800 hrs on. Hasn't been until recent, that the engine is starting to do the usual "burn oil in one cylinder & leak from the other" issue that can happen after the 1000 hr mark. Not sure if the cold cylinder issue is a foreshadowing of that or not.

Mike

 

[Fritz Maurer]

Next time it sits around for an extended period, pull the valve cover off the suspected cylinder, before starting, and observe the valve action....to see if it really is a stuck valve.

Im having trouble understanding how it can run with a stuck valve without dislocating the push rod.

 

[sotxbill]

My terramite has a 20 HP Kohler command with hydraulic lifters, over 2000+ hours. For some reason after it sits for weeks it only starts on the right cylinder for about 10 seconds before the left cylinder kicks in . Both sparks are clean so i discount a spark issue, There is only one carb, so I discount a fuel issue because it runs fine after a few seconds. I'm guessing a valve issue. possibly a rusty valve stem or a hydraulic lifter problem. Do you have a 21 year old kohler command with a similar problem?
When I have time and it warms up. i will remove the valve cover and observe the valves to see if one valve Is stuck open. MY Jubilee exhaust valve stuck open. I sprayed wd40 on the valve stem and inside the cylinder and put the pushrod back in place. After running on 3 cylinders for about 10 seconds the valve broke loose and ran fine.

Do a cold compression test and then a warm compression test... to disavow a valve/compression problem.

 

[Duner Wi]

What can I put in the gas to clean carboned up valve stems.

Marvel Mystery oil in the gasoline. Not in the engine oil.
Multiple successes doing MMO in gasoline only for sticking valves.

 

[Fritz Maurer]

What can I put in the gas to clean carboned up valve stems.

Id put it in both gas and crankcase, if it really is a valve problem. The treatment is pumped up into the valve chamber, where hopefully it can be pulled down into the valve guide by gravity and dissolve whatever is in there during periods of inactivity.

The exhaust valve is probably the more likely to stick from deposits, and I can't see how it could do any good anyway after it was burnt with the fuel.

 

[Geo-TH,In]

Will someone explain why It started today like there was no problem I had a problem yesterday because it sat for weeks. If I started it every day, It will start just fine. I read if I have a lifter problem I would hear a ticking sound. However that would also mean I have good hearing which I don't have good hearing. I'm going to try snake oils in both gas and oil. I have both STP and Lucas fuel treatment. When I get to feeling better I may have to pull the left head and have it rebuilt if snake oil doesn't work

 

[scootergmc]

Because it's probably a fuel issue, not a sticking valve. Didn't someone have a similar issue with a little twin cylinder something or other which ended up being fuel after chasing multiple other dead ends?

 

[MarkB_MI]

Did you put your tainted Jubilee gas in the T-mite?

 

[Geo-TH,In]

Did you put your tainted s J problem haubilee gas in the T-mite?

yes but this problem has existed for many years. the Jubilee gas was just one year old. Remember this is a one time problem. It only happens after sitting for weeks. It started today without a hiccup because it was started yesterday. I don't feel like it is a good reason to remove the head.
the gas tank is above the carb and it came from the factory with a gas solenoid, so it really doesn't need a fuel pump but it has ibe.

 

[Powered By IH]

Will someone explain why It started today like there was no problem I had a problem yesterday because it sat for weeks. If I started it every day, It will start just fine. I read if I have a lifter problem I would hear a ticking sound. However that would also mean I have good hearing which I don't have good hearing. I'm going to try snake oils in both gas and oil. I have both STP and Lucas fuel treatment. When I get to feeling better I may have to pull the left head and have it rebuilt if snake oil doesn't work

Maybe pull the valve cover after sitting for a few weeks, then try starting it and see what happens inside.
Are you getting a backfire through the intake or exhaust?
I don't think you have to pull the head just yet but at least pull the valve cover. If one of the valves are sticky that would be obvious. BUT
10 sec sounds like the time it takes oil to get inside the lifters, and if the lifter drain valve is bad (allowing oil to drain out over 3 weeks) it would take that long to repressurize the lifter? AKA you don't have to listen for a ticking, just pull the valve cover and right away see if the rocker arm is moving enough to push the valve down. if it is, valve issue. If it isn't, lifter issue. A video showing what's happening in the valve cover after sitting would be really helpful too!

I get it, this idea is probably far-fetched and wrong, but I felt I should throw it out there anyways Can't wait to see the replies!

 

[john in la]

I vote you have a lifter going bad. Some snake oil in the engine oil may clean it up enough it goes to working again.

The lifter works fine after one day because it has not had time to leak down. Letting the motor sit for weeks allows the lifter to leak down and the motor to run bad on start up. Once the oil pressure gets up the lifter again pumps up allowing the motor to run correctly.

 

[Duey C]

My take and it's worth nothing more a grain of salt.
Fully agree on a lifter that bleeds-down too quickly, basically shutting the valve off for a few moments.
Or an exhaust valve that hangs up a little. Not stuck.
Like IH eludes to: If an intake valve, you should get barking back in those ten seconds.

What do the small block Chevy lifters do anyway? (Back then, I was told they are so similar they could be or actually were.)
Keep the valve train quiet. That's about it.

They don't pump any oil upstairs. Push rod tips are not hollow. Rockers don't have a hole to pass oil thru the push rod dimple.
Valves are oiled by the mist inside the engine. What I observed from returned engines. Please correct me if wrong.

Perhaps why some early rocker cover fuel pumps iced up and failed. No warm oil up there.