Engine hunting for idle. Mercruiser 260 carb

[CAPTKEV85]

I have a Michigan Motorz 350 roller rocker motor with vortec heads. Motor has 60 hours. At an idle every once and a while the motor will hunt for an idle. It has a edlebrock marine carb. Is it mixture screws? Or something else? Motor is very smooth at an idle it's not rough and the idle is 600 rpms.

 

[jimmbo]

Hunting for idle??? Runs rough? RPM varies or floats over a range?

 

[NHGuy]

600 is a little low, it might be stumbling. Try setting it to 675 rpm.
Make sure the throttle goes all the way to the stop when you bring it down to idle, they can hover a little above idle and require a bit of adjustment.
Also have you checked the idle mixture?

 

[CAPTKEV85]

Sorry for my late response. Worked a lot of overtime. Hunting in my case a slight up and down in rmps. In automotive terms hunting usually results in a idle air control valve. But I have a carb. The engine is not idle rough. Very smooth. I'll bump up rpms and see what happens. Thanks again.

 

[jimmbo]

It might not be the carb. Inconsistent idle speed is often a distributor issue