splashlog, this black fuel is odd to say the least. The only ""black" I've seen in a carb is from gas hoses going bad from ethanol that have not been upgraded to ethanol resistant fuel lines. Did you replace the fuel lines ever or are they really old? The black will look a bit powdery in the fuel, was it dusty black?
How & why is water getting into the spark arrester?
Stumbling to a stop does sound like a fuel or carb issue. Before we tear into the carb inspect the fuel lines and do confirm a good blue snappy spark. And do confirm that the choke is opening and closing completely with a visual inspection.
Did the carb guys use any kind of a sealer on the carb?
Dave Neptune
