As I previously posted, I am having trouble with my Kohler command 20 on a Walker with 48" GHS. It is running rough, missing, and slight consistent backfire while running. I have drained and cleaned gas tank, lines, and carb. Installed new gas filter, air filter and plugs. Still running rough, and seems to be overheating very quickly, even after only a couple of minutes of running at idle. The high heat seems to be coming from only the front cylinder, to the point it heats the muffler to cherry red where that cylinder exhausts into the muffler....and only after a couple of minutes of running. Could this be a stuck or burnt valve? How can I test for that? I can borrow a compression guage, but not sure how to run the test properly. I know there are some great mechanics on this site......any suggestions??? Thanks!!