I have a 89 formula 242. the boat sat for quite a while, anyway constantly changing filters, when I changed the sending unit looked in tank and saw varnish on sides of tank and1/4in of sludge on bottom . I pumped out the old yellow fuel added 10 gals acetone shook the boat on the trailer pumped it out did not work that well. don't want to pull the tank out. fuel polishing work?, use acid? the tank is 105 gal aluminum. anybody else have experience with this or a good solution thanks

I thought I needed to do my tank, found a local place that steam cleans semi trailer tanks, they quoted me $70, so see if you have anything local like that...

thanks I think I am going to try my steam cleaner at the shop with the nozzle at the end of the hose to stir things up and suck the slurry out with a washing machine pump next weekend. its gotta work, it might take awhile but it beats pulling the tank out. even if I get 50% 70% of the sludge out that would be a huge improvement

got the tank clean as new with my steam cleaner. put 800 gals of 200 degree water through it, . and sucked it out with a 65 dollar pump from harbor freight . took 6 hrs better than pulling the tank I could not believe how much crap came out.