In this tutorial, we learn how to replace a primer bulb on a Stihl FS110 trimmer. First, remove the screws around the top cover. After this, remove the bolts around the bulb on the trimmer as well. Once you take this out, replace the bulb with a new one. You may need to blast the dirt away from the bolts to be able to get inside and remove them easily. Once you replace the bulb, make sure to screw the bolts in tightly around the bulb and around the cover. When finished, you will have a new primer bulb and be finished!