Kohler Command 18 dies

JBurd

JBurd

New member
I have a Kolhler Command 18 probably high hours (I bought it used with unknown hours) paired via belt drive with a 5.5gpm 3500 psi pump. Curious if this machine is salvageable...its been running pretty tired under full load for a awhile now (drops under 3000 rpm) but I haven't minded since I soft wash most stuff. The other day after running fine for 5 or 10 minutes it backfired, gave off some smoke and died. I got it going again by playing with the choke and we finished the house but I had to tinker with the choke and restart the engine repeatedly.

Here's what I've tried: new spark plugs, new air filter, taken carb off and cleaned, visually inspected OHVs, tried various fuel cells, oil isn't too old and level is fine. Nothing worked it still runs fine for 5 minutes, sputters backfires than dies. One clue is the right spark is oily, left is white (the new one on the right side got oily after just 5 minutes). I assume I'm losing compression cause piston rings are shot or the cylinder is damaged. Any input? I heard the "sleeve" might be damaged and over expanding after it heats up releasing my compression, but I can't find out if the sleeves are repairable/replaceable. I want to know if its even worth tearing into. Thanks!
 
Rebuild! I am a huge Kohler fan, but a rebuild is probably in order for this one.
 
I have a 26 hp kohler that I rebuilt a few years ago and it has been doing well.

I had another 26hp kohler that locked up on me this year, it had 4500hours on it so I decided I could afford to buy a new engine vs. rebuilding it.

Check the price difference between rebuilding and a new one. Don't pay to much for a rebuild when you could buy a brand new one for not much more.
 
funny that happened to you today. my kohler 18 hp died today also. I have been on line already and new ones go for anywhere between 660 used, and 1600 new. I am thinking that a rebuild willl be 600 to 800.
 
Could be just a valve problem and a leaky inlet valve seal. If you can, take it somewhere that will perform a leak down test on it. That will tell you whether it's the valves or piston/cylinder.
 
I have an 18 hp kholer it has a ton of hours on it,not even sure how many. it is blowing oil by the shaft so i would assume the seal needs to be replaced. question is,,any idea how long should the labor should be in breaking it down replacing the seal and putting it back together if it was done at a proffesional repair shop ? 4 ,6 hours?
 
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A small engine can usually be totally stripped and rebuilt in a couple of hours, unless the customer is helping.
 
Russ Johnson said:
Seal? Crankshaft seal? Output shaft or behind the flywheel? Neither seal requires dismantling the engine. A slim screwdriver can be used to pry them out. Just be careful and don't scratch the crank.
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sorry for the ignorance I really dont know small engines. Its the seal around the shaft the pully is on,would that be the output shaft?

I am going to bring it to the shop tomorrow and get the diagnossis. I used the guy before , he did a good job and he has a reputable shop . I live in Maine and everyone is quite relaxed here so everything takes two weeks longer than the rest of the world.
 
I just saw someone had the Kohler 18HP engines on sale for about $900 brand new. I want to say it was a supplier off one of the boards but can't remember who it was. The Kohler was cheaper than the Vanguard I do remember that.
 
FullBlast said:
I have a 26 hp kohler that I rebuilt a few years ago and it has been doing well.

I had another 26hp kohler that locked up on me this year, it had 4500hours on it so I decided I could afford to buy a new engine vs. rebuilding it.

Check the price difference between rebuilding and a new one. Don't pay to much for a rebuild when you could buy a brand new one for not much more.
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Same answer unless you do it yourself. Where I live the cost of doing anything is not cheap. Get a price from your repair shop but be aware there maybe more digging around by them to figure if there is any other problems your engine is having as well because your diagnoses may not be the exact as to what there's may end up being. So with all that being said you should also price out what a new or a used Kohler engine cost with minimal hours.
Good luck.
 
Both Paul at Power Wash Store and John at Envirospec have Kohler's under $900.

Russ thanks for the leak down test idea, that's exactly what I needed to know, if there was a way to get more info about what's going on without tearing into it.
 
It would be repairable, but don't take any short cuts or get cheap. The cylinder and crankshaft would have to be measured to see how out of shape they are. Parts for a complete rebuild include oversized pistons and rings, connecting rods, bearings, gasket set, valves, springs, and retainers, and oil pump. Machine work would include cylinder boring and valve seat cutting. The valve guides may also need to be replaced. If you are not capable or equipped to do the work yourself (except for the machine work), expect a hefty labor charge from a shop, too.

I had a guy bring me an old cast iron 16 hp Briggs single cylinder engine a long time ago. The cylinder was pretty wallowed out. He wanted me to use his old piston and get a set of oversized rings, then file the ends of the rings to make them fit tightly in his cylinder. I passed on the job, mainly because I knew it wouldn't hold up long, and he'd be back blaming me for the breakdown because I didn't fix it right the first time.

Another option for you is a short block. You'd reuse your sheet metal, charging system, carb, muffler, etc. on a new completely assembled block. If you go this route, I would still recommend reconditioning the heads too.
 
JBurd said:
Russ thanks for the leak down test idea, that's exactly what I needed to know, if there was a way to get more info about what's going on without tearing into it.
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Here's a leak down tester you can get and do it yourself too.
http://www.harborfreight.com/cylinder-leak-down-tester-94190.html
Air escaping from the carb = bad intake valve(s)
Air out the muffler = bad exhaust valve(s)
Air out the oil fill cap = bad piston(s), ring(s), cylinder(s)
 
Russ Johnson said:
Here's a leak down tester you can get and do it yourself too.
http://www.harborfreight.com/cylinder-leak-down-tester-94190.html
Air escaping from the carb = bad intake valve(s)
Air out the muffler = bad exhaust valve(s)
Air out the oil fill cap = bad piston(s), ring(s), cylinder(s)
Click to expand...
One of the many good reasons to have taken Russ's Maintenance and repair class in Huntsville because he sure knows his stuff.

Hey Russ if you see this It would be great to see you do this class in New Orleans as well. I passed this on to those guys that are running the show a few weeks ago. If u do it there or at some other event that I'm going to it's on my list as a must attend class.
 
kohler.jpgkohler2.jpg

hey hey Russ,

thanks for the tip. I got the shieve ? off and pulled out the seal. going to portland tomorrow and pic up a seal. should have it running in the afternoon.again thanks.
 
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