your basic starting point on that motor would be to slowy squeeze the bulb and make sure its firm ,then take off your front motor cover ,hood band and the top cover .look from the rh side (starter side ) and look at the carbs on the rh side of each one and check for fuel leaking at the carbs where your fuel or fuel lines hook up to the carbs ,while gently squeezing the primer bulb .I cant remember if yours has the little plastic covers (usually blue plastic ) on the fuel inlet side of each carb a very notorious area for leaks any fuel leaks or a faulty oring in your fuel connector in the front of the motor these motors are crazier than a diesel any fuel leaks or air intruision they will not start or run very well ...............the big heavy merc fuel connectors are hard on sealing points where they connect to the tank and the motor
