We have a 2003 Walker. It has a 18hp Kohler. The engine provides plenty of power but even since the very first day it will frequently diesel after I shut it down. I talked to the dealer and he recommended letting it idle on the trailer for 15 to 45 seconds after use before shutting it down. That does not help either. It is a newer engine for Kohler but haven't they been around long enough to eliminate goofy things like backfires and dieseling. Anybody else have this problem with their 18hp Kohler V-Twin. Thanks.