Re: 1976 Johnson 85 HP Idling out of control
When idling, the carb butterflys should be closed. You will have to pull the airbox cover to confirm that they are both completely closed when the throttle handle is in neutral. If they are cracked open slightly, you will get rpm rise. The idle on that engine is determined by the idle timing, not by the carbs. To lower the idle, you must retard the timing. Unscrew the large screw head on the spark advance lever. Make sure the throttle linkage is not binding-disconnect the throttle cable at the engine end when setting the idle. It should idle between 650-750 rpm: set when the boat is floating in the water and is in forward gear. It is normal for the idle to rise significantly if idling on the trailer.