XT1 LT50 Running rich at full throttle

[engifineer]

First, I appreciate the forum and am a new member. I purchased an XT1 LT50 mower last summer (June timeframe). It has 19 hours of use on it at this point, so still pretty new. Has run fine thus far until today. It sat more over the winter, but had some use off and on so never sat multiple months without running. Today, it took me forever to start it. Once it started it ran fine on the start/choke position. Runs fine below that throttle position as well. However, once moving towards full throttle, it starts missing, sputtering and smoking. It will carbon a set of plugs in minutes once that starts. I can drive it around the yard and even up a fairly steep hill between my shop and house with no issues if I keep the throttle at or below the start position. I can even bump it just a tad higher over the detent and it will still run ok, but just a bit higher and it starts acting up.

So far I have drained and replaced fuel (running non ethanol 91 octane), replaced the plugs and have cleaned the carburetor. Did not find one trace of anything I saw out of the ordinary when checking the fuel system. The places that were open did not have the fuel filter in stock, but the filter in no way seems to be restricted. I simply cannot find anything that would point to being the issue here. Hoping some others have come across this and have ideas.

It is less than a year old and thus I believe the warranty is still good, but one service place near me said 2-3 weeks at least to get it in. Other one is closed so will have to call them Monday. But given the change in weather, I will have a jungle if I wait 2-3 weeks of course so trying to see if I can get it up and running.

[engifineer]

I should also add, this has the Kohler 7000 series engine

[guyina4x4]

I'd make sure the choke is opening all the way.
Just because the lever moves doesn't mean the choke is opening.
Anything else in the carb usually causes lean conditions.

[R Bedell]

Welcome to OCC..........

[engifineer]

Thanks folks. I am trying to get a better look at what the choke is doing while running today. It will burn your eyes after a few minutes so it certainly seems to be rich as a pig. The last time I started it yesterday I pulled the filter and could see the choke open but appeared to not be all the way open, but need to get a better look at it. It actually appeared to close some when I opened the throttle to WOT, which makes zero sense of course but that was late day, and I had already decided it was well past beer time so just came back up to the house So I shall try again today and report back.

I expect there should be a heat actuated choke control on this somewhere, but am having issues seeing what is going on there. If anyone has input on that it would be helpful. I am used to small engines without a choke control to have some sort of heat actuated control. This does not have Kohlers auto choke assembly on the carb so trying to see how it is done on this one.

I am pretty experienced and decent at working on my cars, but small engines not nearly so much!

[ironman]

FWIW....YouTube video, your model, your problem....
https://www.youtube.com/watch?v=rFwJagvKvfc