Don’t worry—replacing the string in your lawn trimmer is a simple task that you can handle with just a few tools and a bit of Kenyon Noble Know-How.

MTD Southwest Inc. of Tempe, Ariz., said Tuesday it was recalling about 20,000 Troy-Bilt 4-Cycle Gasoline String Trimmers.

The latest batch of string trimmers we're testing includes the straight-shaft Troy-Bilt TB80 EC, $130, and Craftsman 79120, $160.