Member
Join Date: Sep 2008
Posts: 112
IN
07-16-11, 03:36 PM
#1
kohler13 hp engine sputtering
Hi All,
Just bought a JD STX38 with a 13 hp Kohler Command engine. Engine starts right up.
Problem is at any throttle speed. There is a noise coming from the engine that sounds like a hollow popping noise. It sounds like the noise when there is water in the gas. Engine doesn't hunt and surge, just sounds like a miss in the engine. I took the original carb off and soaked it in carb cleaner. Put it back on and no improvement. Put a good working carb on next and still nothing. It has a new correct plug, new air and fuel filter, new gas.
What am I missing in my hunt to fix this? Fuel flow to carb is good also.
Engine number is CV13S, 21509
Thank you,
Cory
Just bought a JD STX38 with a 13 hp Kohler Command engine. Engine starts right up.
Problem is at any throttle speed. There is a noise coming from the engine that sounds like a hollow popping noise. It sounds like the noise when there is water in the gas. Engine doesn't hunt and surge, just sounds like a miss in the engine. I took the original carb off and soaked it in carb cleaner. Put it back on and no improvement. Put a good working carb on next and still nothing. It has a new correct plug, new air and fuel filter, new gas.
What am I missing in my hunt to fix this? Fuel flow to carb is good also.
Engine number is CV13S, 21509
Thank you,
Cory
Last edited by hoosierdaddy58; 07-16-11 at 04:52 PM.
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Member
Join Date: Sep 2008
Posts: 112
IN
07-16-11, 06:29 PM
#3
I looked on the Kohler website. It said a CV13 had hydraulic valves and didn't require adjustment. Maybe I read it wrong.
Member
Join Date: May 2006
Posts: 3,658
IA
07-16-11, 06:49 PM
#4
If everything is working properly, you wouldn't have adjust with the hydraulic setup. But you could have a flat cam lobe = exhaust valve not opening, a burned valve, or a dislodged valve seat. All those things would account for the popping sound you hear.
I believe I would pull the valve cover to see how the valves are moving, then check compression. If low, then pull the head to see where the problem is.
I believe I would pull the valve cover to see how the valves are moving, then check compression. If low, then pull the head to see where the problem is.
Member
Join Date: Sep 2008
Posts: 112
IN
07-17-11, 12:53 PM
#6
Took the valve cover off and valves look to be operating good. Compression test showed 80 lbs. What should it be to be considered low?
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Join Date: Jul 2001
Posts: 16,566
GA
07-17-11, 06:38 PM
#7
On an engine with no compression release, you want no less than 90 lbs, and preferably 120-130. Compression release throws a wrench in the readings though, so your reading can't be trusted. You need a leakdown test. It does sound like a valve problem. Either a sticking valve, cam problem, compression release stuck, or valve seat popping out.
"Who is John Galt?" - Ayn Rand (Atlas Shrugged)
God bless!
Member
Join Date: Sep 2008
Posts: 112
IN
07-23-11, 02:51 PM
#8
Must have been a sticking valve, or something. Dumped some mystery oil in it. Wow, that was alot of smoke. Anyway, I also have a noise whenever I am cranking it over or shutting it down that sounds like a loud click. I took the flywheel cover and I can't see where anything is rubbing or hitting. It doesn't make the noise running. It sounds like it is under the flywheel. Like it is a spring or something. It only clicks once, either when I am starting it or turning it off.
