Carb adjust
 

I was idleing rough and low after this last tank of gas. I adjusted the idle mixture screw on the carb a little and it cleaned up. Could this the change over to winter gas? Or is it normal to have to tweak it in the winter or ever now and then? It was like hunting for rpm up and down about 100 rpm?

Thanks for any input.

P.s. holley carb

I have had to turn up my idle on my Holley equipped trucks pretty much every winter. The spring loaded screw for idle speed tends to very slowly walk out over time. I think it just becomes more noticable when it gets cold and the engine doesn't want to idle easily. (Plus the crap winter fuel additives don't help...)

I also adjust the idle mix screws