wheresthefish
Seaman
- Joined
- Feb 28, 2007
- Messages
- 61
hello, my 9.9 johnson is running pretty good except when i turn the trottle to high speed and back down to low speed it immediately makes a coughing sound like it is sick. i would think that it should just smoothly make the transition from high speed to low speed without making a coughing sound. does anyone know what could be the problem. i did change out the carb to a 15 hp carb of the similiar year. my motor is a 1992. thanks for all the help!!!