Kohler 22hp mower running rough

[moosestang]

I've got a craftsman 22hp kohler engine mower that just started running rough out of the blue. It runs rough at idle, but ok with the blades engaged. if I choke it just a little bit it smooths out, it also smooths out if I pull one of the spark plug wires. throttle position doesn't really matter. I'm guessing it's running lean due to an intake leak or clogged jet, but why does it smooth out under load?

I don't know how many hours are on the mower, nor do i know the maintenance history. It sorta came with the house we bought, i paid the previous owner $200 for it.

I'm uploading a video, stand by.

 

[moosestang]

 

[ILENGINE]

Partial use of the choke to smooth out the running indicates a partially clogged jet. Carbs are set up with two fuel circuits. And idle circuit, and a high speed circuit. An en gine running without a load is acually running on the idle circuit of the carb, when you apply a load to the engine the throttle butterfly opens which causes a vacuum on the high speed circuit and uses the high speed jet.

So you have a partually clogged idle circuit.

 

[moosestang]

Thanks! I'm going to try cleaning the carb. I haven't messed with a carburetor since I tried to install a jet kit on my 1996 yamaha fzr600. I screwed that up royally, hopefully this turns out better.

 

[moosestang]

Took the carb off, removed bowl, sprayed the thing with the garden hose, blew it out with compressed air. I noticed when taking the bowl off that the float didn't sit level with the body, but it did after I got done cleaning it. I did not remove the jets. I didn't have a screw driver that would fit in the small jet and the main jet wasn't going to budge! the thing would damn clean for such an old mower. No varnish inside at all.

No carb cleaner at the house, so I used wd40. let it sit, sprayed it out with air, did this several times and it now purrs like a kitten again. There was some crude under the rubber plug for the idle jet, I think it was restricting the hole to the main jet.

I noticed that the throttle linkage didn't really move when closing the throttle. There was a spring hooked to the back of the linkage that didn't appear to do anything, so I hooked it to the throttle arm. Is that the way it's supposed to be?

spring not hooked up, see it behind the linkage above the big spring on the left?

Unhooked it and hooked it to the throttle arm.

 

[Jammer48]

Did you ever get this figured out?