Just replaced the carburetor on a 6 hp lawn mower because it was filled with varnish from old gas. Plastic tank and adding a fuel filter. It's interesting that you can purchase a new carb with gaskets and fuel filters for $11 from China.
Last year I bought a carb for my Murray Snowblower for $12.35 shipped from China. It looked like an exact match to what was on there. And ran like a top. I won't waste anymore time cleaning and old carb out , if a brand new one is so cheap.,,,