I have an old John Deere SRX-75 riding mower with a 9 Horse Kawasaki fc290v engine on it. It has always run perfectly until last week after my wife used it to mow the lawn while I was out of town. I can't be sure, but I have a sneaking suspicion that she ran it all day with the choke partially closed. ( I think she pushed the throttle lever too far foward.) Anyway, it now starts if you choke it and will slow idle, but if you try to fast idle it, it dies immediately. However, if you hold the choke lever so the choke closes, it will run with a higher throttle setting. I have tried checking and resetting the throttle linkage, choke and governor arm, but it still dies when you increase the throttle past idle. Is this likely a carb problem - i.e. the jets or something gunked up and need cleaning? If I need to clean the carb is there a schematic available for this model? Should I try something else before I try cleaning the carb? Any ideas would be greatly appreciated.