I have a Homelite UT32600 26cc string trimmer. The problem is that it just stops running after about 5-10 minutes of use. I've replaced the fuel pickup/filter, fuel lines, carburetor, spark plug, fuel cap, and muffler/spark arrestor. The carb adjustments seem to be correct when it is running. No problems starting initially and it will restart after a couple of minutes but will stop fairly soon afterwards. Any ideas?