hi i am new to the whole outboard engine deal but i bought a boat with a 1989 johnson jet drive outboard its 50hp on the head and 35 at the jet ....the thing will not run it will start for about 5 secounds and shut off it has good compression and i just cleaned the carbs real good and its doing the same thing..... any ideas??? vacum leaks? fuel? it will start but will not run or idle please help!! thanks