Ok, well I have a Husqvarna 123LD String trimmer. I bought this trimmer last season mainly for the purpose of using it for different attachment such as the hedge trimmers. Anyway about 2 weeks ago I noticed that when it was running it would lose alot of its power, that lasted for about 2 days then it would run for about 5 mins and just shut off completely. Then it would be almost impossible to start again. So I started taking it apart first thing I did was to look at the cylinder but it was not scorched. I then changed the fuel filter and tried a different gas cap, it would still run but stop. So I started reading the owners manuel. It was talking about the emission and converter in the exhaust so I took the muffler off and heated it with a torch. All kinds of soot and debris burned out, I thought for sure that that was the problem that trimmer wasnt getting enough back pressure and the exhaust was shutting it down. I put it back on all clean still does the same thing. So yesterday I put on a new spark plug and had it running for the longest it has been on for a while it idled for a good while as I started playing the carb. I thought I had it to a point where I thought I could use it at work. Tried it yesterday to weed wack a hillside, would run, but not with alot of power, then I noticed it would only work if I was working up the hill and the gas tank was down. If it was any other way it would just quit. This leads me to believe that there is a fuel problem, almost like the machine is running out of gas? Does anyone have any advice that could help me out? THANKS!!!