Can anyone give me some advice on this? I have a FS110 with 25-2 trimmer head. It runs excellent and starts easily until under a load at high RPM's. It will rev fine until I attack really tall grass. it almost seems like an electrical problem as it cuts right off. I can keep it running if I close the throttle-it goes to idle. Running clean fresh gas, filter looks good and unit is about 2 years old. Never had the Spark Arrestor out but not sure if this would do it. Any help is appreciated.