I was running at top rpms. The engine changed pitch, I was listening, wondering, then she took off running mega rpms, throttle unresponsive, kill switch quick. Engine shut down. Choke shaft sticking out...hmmm wtf? Slipped shaft into carb, attempt restart. Nothing. Turned air filter wrong side in to choke engine. Engine starts, misfiring all over the place. Disasemble air snorkle. Remove carb. Choke flap screws gone. They are little, They are brass. At my shop now, old carb for missing screws, will repair in the morning. Question: Will brass melt quickly in combustion chamber? If it still runs probably no damage? What do you think? Put her back together and run her? Has this happened to you? Permatex the screws? Kawasaki sample engine on Exmark,the FH770D is down, blown head gasket, need to use the Hustler FH680V mower tomorrow or no steaks for dinner! thanks' kenny.