A relative has had my L555 for quite some time and it just came back home with a fuel tank full of sludge. I could only get about 15 minutes out of new primary fuel filters and now it acts like the pick up in the tank is stopped up. Has anyone ever removed or cleaned one of these tanks? How much trouble is it to remove it? I've not had a good chance to look it over good yet to see but I'm expecting that it's a real pain. Thanks in advance for any and all help.