Stihl FS 90R Trimmer Maintenance

Changing fuel filter, air filter, primer bulb, spark plug, gearbox grease, and checking valve clearance. Valve clearance check uses same part# for all 4-mix trimmers. Errata: I love how this video gets more dislikes than any of my others. Humans are up in arms “DON’T TELL ME TO READ THE FUCKING MANUAL!“, idiots lol.