Mecrury 40 hp HELP!

[<AlabamaCamper>]

Please help. My boat has been in the shop on and off since July and still it is not fixed.
This what I have, it is a 1996 40 Mercury outboard and I have it on a pontoon boat. What happens is that it will run about 10 minutes then it want idle and it want take hardly any gas. They the boat mechanic went into the cards redid them gave me a tune up but he says it is sludge in the bottom of my gas tank. Well what happens he says is he cleans out the carbs and then after ten minutes or so of running the carbs get dirty again and it quits running. It should be noted that the carbs start leaking gas when this happens also. When I first took it to him it didn’t leak any gas just would die after 10 minutes or so running. What do you think? H did replace the fuel hose and bulb also. I emptied out the gas tank and rinse it out with gas cleaner before refilling it with good gas today and it did the same thing. HELP!

[<Motorman_43>]

The best I can suggest is to get a new fuel tank,hose and primer bulb. Also clean or replace all the fuel lines from the fuel pump to the carbs. It's just going to keep on picking up the crud at the bottom of the old tank and foul up every thing. The crud has gotten into the carb needles and seats so they aren't closing and just flooding things out. The carbs are going to have to be recleaned and rebuilt.Clean out the filter at the fuel pump. That motors fuel system needs a complete fieldday done to it.