Originally Posted by Junglerot
Use caution with simple green and aluminum, it can oxidize the carb if left too long. I do believe they make an aircraft version that is aluminum safe, but I prefer to use a 50/50 mix of pine sol and hot water.
Pine Sol does a great job on carbs. I also use it 50/50, and just leave the carbs in it overnight. It won't attack any of the metals in the carb, but it is conductive enough to allow a little galvanic corrosion because of the dissimilar metals. The little bit of "bloom" you get on some of the parts will wipe off.
It would take the carbon off of biopig's valves, too; but it would take the paint off the head. Carb cleaner, a bottle brush, and elbow grease will get the exhaust ports clean enough.