been having troubles for a long time on cold starts on my 1985 johnson 15 hp. someone said its probly to lean and needs the mixture adjusted. most of the time it will start with the choke at full and immediately close the choke after fire up. is the mixture control the only pin coming out of the carburator that has a control nob on the face plate of the engine? any help from someone would be greatly appreciated. i wanna go fishing.lol