Lock Nut on Idle Adjust Screw? Would This Be a Problem?

[minuteman62-64]

The idle adjust screw on my old Mariner vibrates out of adjustment after awhile. I usually notice this on the water when it's a PIA to re-adjust (have to remove cover and part of electric choke assembly to get at the screw). And, when the idle speed gets below 500 rpm it doesn't pump enough water so tends to over heat. It is what I assume is a standard setup - a screw/spring combo.

​Any issues if I would put a nut on the screw to act as a lock nut?

 

[ondarvr]

The motor will instantly self destruct.




​The motor has no clue whether there's a lock nut there or not, and it really doesn't care.

​A couple drops of Loctite might work too.

 

[Scott Danforth]

or some vibra-tite https://www.vibra-tite.com/

 

[minuteman62-64]

Took a closer look today. Turns out there is not room for a lock nut unless I ditch the spring (which, with a lock nut is probably redundant anyways). More important, looks like the spring, sitting there in a compressed state for 35 years, has lost a little of its compressive ability. So, rather than blow $0.12 and a trip to the hardware store on a nut, I stretched out the spring so that it is actually compressed when the screw is in the position for the idle speed I want. I'll see how that works.

​More important, I noticed a piece of black electrical tape on the carb inlet housing. Pulled it off and, lo and behold, there's a nice little port that lets me get a screw driver right in to the idle screw. Don't know why I never noticed it before or why someone (PO?) had put it there. Anyways, appears what I thought was a problem isn't really much of a problem.

 

[jimmbo]

What exactly are you trying to adjust? The only place on the throttle linkage with a spring that I know of, is the part that allows the carbs to open once the timing is fully advanced?
Picture please

 

[minuteman62-64]

The screw that adjusts the idle rpms. It is inserted through a compression spring designed to keep the screw (and idle speed) from "drifting."