1985 Johnson 9.9 Idle Speed Adjustment

[rogerkaputnik]

How do I decrease the idle speed on the 1985 Johnson 9.9 HP outboard? Otherwise, this motor is running fine.<br /><br />thanks<br /><br />RC

 

[fireman 757]

Re: 1985 Johnson 9.9 Idle Speed Adjustment

Where your throttle (tiller handle) goes into your engine, right behind it is about a inch to inch and a half "button". It is plastic, probably black. turn it, then rev it in neutral, let it come back down and then turn it some more until you get it where you want it. I assume that you have already adjusted you low Idle adjustment on your carb. It is usually marked slow/fast or rich/lean. Turn it in all the way and BARELY seat it. Turn it out one and a half turns. Screw it in at 1/4 turn intervals until it starts to cut out. Back it out and within that last 1/4 turn you should find your best idle.

 

[Boatist]

Re: 1985 Johnson 9.9 Idle Speed Adjustment

Roger<br />Fireman has it right. My plastic idel speed knob is hard to turn. Many older 9.9/15 have a lot of play in throttle pivot right below idel speed adjustment and that can be shimmed if necesary. To adjust the low speed jet I turn it in (lean direction) until it starts to chough then back out until runs smooth. After that I pull knob off center pointer stright down and push back on.