I'm Bill Elzey, with Showplace Lawns. How to repair a weed eater, or a gas trimmer. One thing that you would want to check, is your spark plug. Make sure that it is clean, unplug it, take it out. Using a wire brush, clean it off. You may want to rinse it in a little bit of gasoline, just to get it nice and clean. Also, the area that you put the plug back into, should be cleaned out as well. A good way of doing that, is with the rag on a screwdriver, and then just kind of clean out the whole, put your plug back. Make sure that it's in there good, but not too tight, put your wire back. Another area to check is your air filter, and a lot of times when the air filter gets clogged, it won't let the engine breathe, and it won't start, or it won't run right. A lot of weed eaters now, have a sponge type of air filter, that you basically take in, and wash. Hot water and dish detergent soap, liquid dish soap, works wonders. Just wash it really good, maybe knock the dirt off, before you take it in and wash it, and again, take the rag, clean around the area where the filter goes in that housing area, and put the filter back. Those are two key areas on maintaining and repairing a weed eater.