steveair, What was the outside temperature the day that happened? Also what was the humidity that day as well? Does your engine have an anti-icing kit installed. Having grown up in northern Iowa we found icing up in the carb to be a big problem. This can happen in temps as warm as 35-40 degrees. The air is super cooled as it goes through the carb. The crankcase on the kohler engine is attached to the air cleaner system as well. This provides the moisture to cause ice build up in the carb. My next suggestion would be that if the unit acts up again, immediately remove the air filter and look down the throat of the carb. If ice is present you will need an anit-icing kit to keep it from happening in the future.