RE: Summer Carb Adjustment.
It is what it is, no one can say. Each engine will be different. Ever see the needle twisters? Those are the guys at the field that will twist the needles before each flight. I don't play that game, if the engine ran well last week it will run the same this week. I make a bit of change if I put on a new prop of a different size and as our weather starts changing. With our weather it is a very slow change from summer to winter. Last weekend it was 98 and today it is colder and over cast, it isn't enough to bother the engines enough to twist a needle. Last month I took out a plane that hasn't flown in a year, my only two stroke, it ran perfectly without any adjustment. Like Jester pointed out, there can be a lot of little things to make engines all run a bit different. Just changing fuel brands can do it. Just tune your engine the way you want it then leave it alone. Come fall it will change a tad. It doesn't care if it is 90 or 115 in our climate but it will change from now and when it is in the 60s. Mine don't like to start first thing in the morning when we get into the 30s and 40s.