idle adjustment

tallcanadian

Captain
Joined
Sep 7, 2006
Messages
3,250
where would the idle adjustment screw be on my carbs. my motor runs just a tad too slow. i have a 1985 45hp commercial johnson.
 

fireman57

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Joined
Aug 24, 2004
Messages
3,811
Re: idle adjustment

You are probably better off setting the idle up by adjusting your throttle cable at the engine. Take it off and use the little wheel to make the cable shorther and then put it back in the holder. There should be a bolt on the side of the engine with a rubber tip that serves as a stop. Ideally, you would use it to do it with but I have found that the cable is easier.
 

Silvertip

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Sep 22, 2003
Messages
28,771
Re: idle adjustment

Do not adjust the throttle cable to change idle speed. The adjustable trunion on the cable is not for idle speed. Its to adjust cable length. In fact, to properly set idle speed, the engine should be in the water (not on muffs). Disconnect the throttle cable and then set idle mixture and idle speed. Turn off the engine and bring the cable end up to the throttle linkage while holding the throttle linkage against the idle stop. If the cable end does not match exactly with the linkage attachment point, adjust the trunion (threaded barrel) so it does. Reattach the cable.
 

Silvertip

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Sep 22, 2003
Messages
28,771
Re: idle adjustment

Post a picture of your engine from the throttle linkage side and I'll point it out. Or, make a visit to your local library. They generally have service manuals. If you don't want to do that, you need to remove the cowl, and have someone move the throttle lever while you watch the linkage. You will eventually find a screw that hits a stop when the throttle is closed. The reason I'm being a little sensitive here is that you can easily mistake the idle screw for a timing adjustment screw and really mess things up. Stay away from the carburetors -- the adjustment screw is on the linkage arm.
 

fireman57

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Aug 24, 2004
Messages
3,811
Re: idle adjustment

Silvertip is right. The screw he is talking about is the bolt I was talking about with the rubber tip. You can screw it out for lower idle or in for more then adjust your cable. Like I said in my first post ideally that is what you want to do.
 
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