Fuel problem 1984 Yamaha 1000?

I have a 1984 Yamaha 1000. It is getting to much gas the gas is blowing out the exhaust. The bike will start and run but when I turn it off I have to remove the plug and dry it out before it will start again. The higher I rev the bike the more gas sprays out the exhaust, it uses an electric fuel pump. A machanic has taken the carbs apart three times, clean and adjusted them but can not solve the problem . The mechanic has tried another fuel pump, which he got from salvage, but still the problem persists.