I had the same thing happen to me. I read somewhere else on this answer forum how to correct the problem & now can't find his answer (which was more complete than mine). I went to Home Depot & purchased an Echo fuel line (less than $3.00). When I got home, I removed the old fuel line from the tank to the carb., then with a coathanger with a small hook, fished out the fuel line & filter that was inside the gas tank. I removed the filter. When you're installing the new line, cut it at an angle to push it through the opening in the gas tank, fish it out with the coat hanger. Cut the end again to make it square. Connect the filter & place this back into the tank. Connect the other end of the line to the carb. & you should be good to go. Sorry, can't help with the plug gap or other info. I installed a new plug & just went with the factory preset gap & it works fine.
Bud, August 2007