I have a John Deere trimmer that is quite old but still does the job but unfortunately it has outlasted parts availability, The model number is XT250B. I believe that it was manufactured for John Deere by Stihl. I need conformation of this assumption which would give me a starting place to locate a carburetor, but in searching the internet can't find any carburetor that fits that trimmer. There is the possibility that it is available only as an aftermarket item which if that is the case it will have a whole different part number than the original.