Idle adjustment

[89retta]

Last month i bought a 81 140hp sport Evinrude.Engine runs great,but the idle is a bit low.The idle screw is already turned all the way in so i cant turn the idle up.Is there another adjustment or is something worn as to why the po owner has turned all the way in?Thanks for any help.

 

[Haffiman]

Re: Idle adjustment

Start by doing a compression test of the engine.
If that turns out good, do a 'link& synch'.
The important part is to get the timing pick-up point correct as well as the carbs in synch.
After this, try to adjust the idle.
A factory(OEM) manual is a must to get it correct for your engine.

 

[Dhadley]

Re: Idle adjustment

If the motor is running correctly on all 4, the carbs are clean and the sync is correct you may have some sticking rings. Not uncommon especially if the top capable rpm is too low. If the motor is running correctly try doing a good decarb. That should help.

 

[89retta]

Re: Idle adjustment

Checked compresion when i bought it 120lbs on all four.Engine runs perfect 5000rpm wot.Top speed is 43 mph.It just idles low.Like i said the idle screw is turned all the way in already.Can i adjust anything else?Or am i missing something that is worn out and that is why the po has it turned all the way in so it will idle.

 

[Haffiman]

Re: Idle adjustment

As mentioned above, a 'link & synch'.
Most people miss out the adjustment of the link between the arm and cam when aligning the cam up for the pick-up timing point and just use the roller adjustment and idle screw.
Do it all from scratch according to the OEM manual.
But before starting to adjust, do the de-carb and check engine temp at idle.