1962 Evinrude Lark IV 40hp

[Wardejii]

Boat ran great first two times out but struggled this trip.
Thinking back on things I may have done.
I noticed, what I now know is the idle screw located on front of controller Was dangling there so I screwed it in.
This trip had trouble with the boat idling and once I was moving it had no get up and go, like something was holding it back.
So I guess I will back that screw out, leave it dangling and see if that will alleviate the problem. I still would like to increase the idle speed a little bit.
Help...

 

[F_R]

That screw on the control has nothing to do with how it runs, only how far you can pull the throttle lever back (how slow an idle)

Your description suggests it is running on one cylinder.

 

[racerone]

Have to agree.----These motors will run / sound amazingly healthy running on one cylinder.-----So do a compression test.-----And does spark jump a gap of 1/4" or more on a proper spark checking device , yes or no ?

 

[oldboat1]

You might try running with the choke in the manual position in case the auto choke needs attention. Additionally, I would pull off the carburetor and disassemble it -- soak in lacquer thinner, and clear all openings with carb spray and thin wire. Open up the idle passages on top (domed plug) before soaking.