EDITED to better fit the "how to ask questions" posting rules 
Volvo Penta 5.0 GL, Ser#: 4012035992
I just bought a used 203 with the 5.0GL PEFS engine, low hours (approx. 300), but the boat has been sitting for a few years with minimal starting and no usage. It started when I bought it, but coughed white smoke, and I haven't tried starting it since. It actually wouldn't start after the first time and the owner stated that he thought it did not have any fuel in it. He said they added fuel stabilizer a few months ago, but none prior to that.
My question is: If gas was left sitting in boat for 3-4 years, what would be my best course of action prior to starting again? Is it necessary to remove and clean the fuel tank, lines and fuel filter to clear out any old gas and/or varnish from old gas?
Again, I just bought it and although it was well taken care of when the previous owners used it, it has been sitting for a while with little to no maintenance.
Volvo Penta 5.0 GL, Ser#: 4012035992
I just bought a used 203 with the 5.0GL PEFS engine, low hours (approx. 300), but the boat has been sitting for a few years with minimal starting and no usage. It started when I bought it, but coughed white smoke, and I haven't tried starting it since. It actually wouldn't start after the first time and the owner stated that he thought it did not have any fuel in it. He said they added fuel stabilizer a few months ago, but none prior to that.
My question is: If gas was left sitting in boat for 3-4 years, what would be my best course of action prior to starting again? Is it necessary to remove and clean the fuel tank, lines and fuel filter to clear out any old gas and/or varnish from old gas?
Again, I just bought it and although it was well taken care of when the previous owners used it, it has been sitting for a while with little to no maintenance.