4.3l merc idles low and stalls when in neutral.

[Dave87]

Hi everyone,

So my engine does seem to idle high enough to keep running.

Any thoughts on what I should do?

I'm not exactly sure how to adjust idle speed.

It's a Its a 1991 4.3l mercruiser

Thxs

 

[Kola16]

Do you have a tachometer? What is your idle speed? You should be around 650-700 RPM's.

Do you have a carburetor or is it fuel injected (EFI)?

 

[Dave87]

I do have a tachometer. It's a 2 barrel carb.

I believe I fixed the issue by adjusting a screw on the carb which brought up my rpms to 750-850. Is that to high ?

Before adjusting it It was at 250-500

 

[Kola16]

Too high? Possibly, but not for certain. You risk slamming into gear too hard when shifting gears which is an expensive fix. It sounds like you found how to adjust the idle on the cable going to the carb. Just back the threaded barrel off one or two turns till it is in the 650-700 RPM range.

 

[Dave87]

Will do thanks!!

 

[Rick Stephens]

Idle is not adjusted with the cable barrel. There is an idle adjustment screw on every carburetor. Read the Mercruiser manual and set idle properly.