Ask the Editors: Green Gunk in Carb
Green is the telltale sign of corroded cast aluminum. Contrary to common misconception (because most people realize aluminum is resistant to weathering/ rust) aluminum actually corrodes very rapidly, more so in fact than most other materials on exposure to oxygen (oxide forms almost immediately). Yes oxides form on cast iron and steel as well but at a decreased rate by comparison.
What’s important to realize though is that unlike iron and steel, which corrode right through once the process begins, the green corrosion littering up aluminum is likely just a surface film that can be cleaned.
A little elbow grease can usually remove such corrosion and there are a wide variety of automotive products (such as Loctite’s Aluminum Jelly) that break it down immediately. Just be sure to completely remove such chemicals from your carburetor before reassembly.
