This is FS55 carburetor without priming. Reason and description are in the video. Few more details - At 1:22 you can see a picture of dismantled carb, and one like "piston" with rubber O-ring is marked, that O-ring is problem, change this O-ring, or complete "piston"....
This is a quick how to video on replacing the primer bulb on a Stihl FS55 trimmer. This will work the same on the FS45 / FS65 models as well. This primer bulb is approx $3.00 - $4.00 at your local lawn mower repair shop. This can be done in as little as 5 minutes, and...