Well, as always, it seems that all my stuff all breaks down at the same time and it always picks the worst possible time. A few weeks back, all the mowers broke the same day and on that same day my regular use 2 cycle stuff started getting stubborn on me. Well, now it is yesterday, but my trusty Stihl trimmer laid down on me, and so did the Echo blower. Errr! Well anyways, about the same thing happened to me less than a year ago. Before they would crank and then act like they were running out of gas and die. Well, that mystery turned out to be the fuel lines. I replaced it all on both. Now, this time around, both will crank and run, but neither will accelerate. They just choke, fall on their face and die if I don't let off quick enough. They were both also a little stubborn to prime. The lines seem ok. So I figured it was a good time to go ahead and change the fuel filters and air filters. I did this to the Echo first and it didn't help. But during the process of messing with it I decided to mess with the high speed screw. After running it up and down within it's capped limits a few times, it cleared right up and now runs fine. My stihl trimmer on the other hand is a different story. I changed out the filters and set all the carb screws to spec. I even removed the muffler to clean the carbon from the exhaust ports. There was nothing reall there but a little gumming around the edges, which I cleared and put it back together. But it still would not accelerate. The high speed screw will only adjust 3/4 of a turn within it's capped limits and does not help. But the low speed screw has a lot of adjustablity. No capped limits. So I ran it out farther and farther. Finally I got it working. I used a full tank of gas and when I stopped to refuel, it went right back to the same thing. I've messed with it and messed with it. I can't get it going. But as a side note, while changing the filters out, I spilled some of the gas out of the tank onto the floor. I stood in it while working a bit more and when I stopped to clean it up, I realized it had melted the rubber soles of my sneakers!!!!! Rubber just rolled right off when I wiped the bottom of my shoes! What in the heck gives with that????? If it did that to my shoes, geez then, what is it doing to my fuel lines???? And why would the gas be doing that? I'm not sure what to think now. Is this my problem? Is something else wrong? Or do I need to figure out how to remove the limit cap on the high speed screw? What? Not sure what to do and this sucks. It was already a short week and now I'm even further behind. Errr!!!!!