I have a 1994 Johnson 50 hp 2 stroke which had a rough idle and would only make half throttle. My mechanic change both plugs and the power pack and the rough idle went away but I still had the half throttle problem. He took off the carb and cleaned the needle and seat and it then ran good making full power. I let the boat set for half a day and when I went to run it again I had the half throttle problem again. I can push the power lever all the way forward and wait for about 15 seconds and then it kicks in and goes to full power. It has done this twice now and I still have this problem. Do I have a carb problem that needs further help or any other suggestions?
