Recently I cleaned the fuel tank. Poped the hatch . Removed the fuel gauge sending unit. I orders a new one . The nut on top was rested. I removed all nasty grime sludge from the tank. I then acid washed the tank over nite with 70/30 water and muriatic acid. I neutralized the tank with water and baking soda. Then flushed the tank 4 times with water.Found out the tank was aluminum , and in great shape. I made giant Q tips with stiff wire and rags, and removed all water I could, which was 99%. The other 1% I removed by running my shop vac on blower for about 3 hours, with a towel over the fuel gauge hole. Put white rag /q tip back in tank. Clean👍🏻. I see 640 or so have looked at the post I think that’s awesome. 20 of those views are me. I have a question. What is the best gas / stabilizer to run in my 1987 2.5 Mercruiser motor?