Small Engines (Lawn Mowers, etc.): FS66 Stihl, adjustment screws, vent hole

Question
Unit will crank only runs a few seconds. Carburetor starts leaking and little droplets of gas are sprayed from carburator. Gas tank is also pressurized and gas blows out vent hole in cap. If I make it run longer than a few seconds, it will blow all of the gas

ed

Answer
Start by cleaning the fuel system.  Drain the fuel.  Clean the cap and tank. Install new filter and fuel lines.  Inspect the insulator block the carb mounts to.  Purchase a new carburetor kit and all new gaskets.  Take carburetor apart and clean all passages with a wire from a twist tie.  Blow out with compressed air.  Install new carburetor kit per instructions.  Lightly seat the adjustment screws and then back off 1.5 to 2 turns.  Install carburetor with new mounting gaskets.  Attach and adjust throttle and choke cables.   Install new air flitter attack lines.  Put fresh fuel in tank.  Remove the muffler and be sure the exhaust ports are not plugged.  Install muffler and put a new plug into it.  This should take care of the problem.