Thanks, Mark / Ohio. Your hint about the gas cap vent being clogged was right on. I had done all the usual checks and cleans, etc. to my 17HP Kohler Craftsman rider to no avail. I was stumped. It would run perfect for a few minutes and then choke down. Cleaning the gas cap vent did the trick. Thanks again for coming back and posting that follow up comment when you were helping Rikki Sixx back in September. Rick.One thing I forgot to mention that bit me in the behind again only about a month ago is the vent on the fuel cap being plugged. Just loosen or pull the cap with it running and see if the idle comes back and the high end smooths out.
I found that to be the issue with my MTD push mower after I had pulled and cleaned the carb trying to solve it. Oh well, 20 years since I last pulled the carb on it so it was probably due for a cleaning anyway.
My old Jake rider had the vent plug on it once but it would just run out of fuel in about 15 minutes and stall.