Erratic Idle

[dblanton]

I have a 1981 75 hp Evinrude, when I pull the throttle back to netural the idle speed may be high, the next time it maybe normal or low. I have set the idle sync according to the manual and checked the high and low speed timming, cleaned and inspected the carbs and everything seems to be fine, could ther be a power pack problem?

dblanton

 

[Jason Edwards]

Re: Erratic Idle

I had the same problem and what I found out was that my throttle cable was adjusted too short. The cable would not extend quite far enough to let the low idle adjustment screw do its thing and because of this it wasn't stopping in "exactly" the same spot every time. This caused my idle to sometimes be a litte fast, slow, or normal. After I adjusted the cable it idles perfectly every time. This may not be your problem but it was mine. You said you cleaned your carbs but did you rebuid them?

 

[dblanton]

Re: Erratic Idle

I had the same problem and what I found out was that my throttle cable was adjusted too short. The cable would not extend quite far enough to let the low idle adjustment screw do its thing and because of this it wasn't stopping in "exactly" the same spot every time. This caused my idle to sometimes be a litte fast, slow, or normal. After I adjusted the cable it idles perfectly every time. This may not be your problem but it was mine. You said you cleaned your carbs but did you rebuid them?

 

[dblanton]

Re: Erratic Idle

I haven't rebuilt the carbs yet but I was planning on doing so if I didn't find something else that was causing this problem. Thanks for the tip on the cable adjustment I will check that. I did notice that some times when I pull the throttle back to netural that the fast idle lever moves up slightly.

 

[Theoutdoorsman]

Re: Erratic Idle

dblanton.............. the fast idle lever, moving up slightly when shifting, is a good indication the throttle cable is out of adjustmet. Definitely take a look at it and make certain your idle stop screw is reaching the stop every time you shift as Jason Edwards suggests. Sounds like a minor adjustment AND an easy fix. You've probably noticed this aleady, but I'd bet the throttle controls are a little stiff and aggravating when shifting sometimes huh?

 

[tashasdaddy]

Re: Erratic Idle

if the cables are original, and have ever been around salt water, they may be on their last leg. they are 26 years old.

 

[dblanton]

Re: Erratic Idle

Thanks all, yes the throttle controls are a little stiff and aggravating when shifting, the cables are original but have not been around salt water. (not alot salt water in central Oklahoma) I will take a close look at the cables and the adjustment and make changes as needed.

 

[dblanton]

Re: Erratic Idle

Hey everyone, I checked the controll cables and made the necessary adjustments etc, throttle is hitting the idle adjustment screw as it should and the cables are easier and free now, everything seems ok with the cables but I still have the same erratic idle problem. Is it time to rebuild the carbs or should I look at something else?

 

[Theoutdoorsman]

Re: Erratic Idle

dblanton........... When you move the throttle back to the nuetral possition, and while looking at the tacometer, are you saying the rpms go up and down while idling or simply high and steady one time, and low and steady the next? How much variation in rpms are we talking about.

 

[dblanton]

Re: Erratic Idle

The rpm is high and steady one time, and low and steady the next time, the rpm will vary from 1300 on the high end to 650 on the low end and sometimes will be around 750 to 850.

 

[Theoutdoorsman]

Re: Erratic Idle

dblanton........... What is the model number on your outboard?

 

[dblanton]

Re: Erratic Idle

Sorry it took so long to respond.. my job requires me to travel alot & I've been out of town, but to answer your question about the modle # it is E75TRLCIM