Kohler 19 HP Courage was running rough. Removed, cleaned, and rebuilt Walbro carb (new needle valve and seals). Changed oil, replaced fuel filter, new carb gaskets, new fuel solenoid, new spark plug. Fired it up and it ran like a champ for the 1.5 hours required to cut the yard. Next day, someone else attempted to start the mower with full choke for an extended cranking time. Would not start. Removed air filter and the choke butterfly was stuck closed. Lots of fuel in the carb. Reset the choke and it started up but was running very rough and about 1/2 power on full throttle. I smelled smoke, opened the hood, and the exhaust manifold and muffler were RED HOT! I immediately shut down the engine and let it cool. Removed muffler - it is toast. Removed and re-cleaned carb. Now, when trying to start, engine just cranks and doesn't fire. Tried with starter fluid in direct into cylinder - no luck. Spark plug is dry. I'm out of ideas. Any suggestions? Had anyone seen where a muffler has gotten red hot?
The red hot muffler may have been caused by a leaking carb, since you said the carb was full of gas. Kohler had issues with the fuel solenoid a few years ago on Troybilt riders since MTD moved the muffler closer to the engine, even though the denied it. the overly hot muffler may have cooked the fuel solenoid on the carb, which would be the cause of the no start situation now.
Thanks very much for the guidance. The Kohler 19 is on a Craftsman 42." Your theory makes sense. I have an older solenoid I can swap out to see if it helps. Even if the solenoid is toast, wouldn't the engine at least fire if I spray starter fluid directly through the spark plug hole into the cylinder, replace the plug, and key the starter?
