need verification on idle mixture screw ?

[supercab78]

I have a 1984 140hp IO mercruiser with a Merc 2 barrel carb. It has just ONE idle mixture screw. Does this one screw effect the idle circuits of both barrels at the same time? Is it treated (adjusted) the same as a regular carb (in= lean, out= richer) ? The reason I ask is right now when adjusting it there isn't much change in engine RPM. Before I tear into I thought I'd be sure of how it should react to adjustments.

 

[Don S]

Re: need verification on idle mixture screw ?

Yes, it's just a single screw (Mercarb) instead of a double screw (Rochester) carb. Does the same thing, just one less.

 

[supercab78]

Re: need verification on idle mixture screw ?

OK; thanks Don. I didn't think it was responding to my adjustments right. I'll get a kit and take care of it