1. Fuel mixed 50:1 (1 litre of petrol, 20 ml of two-stroke oil), shaken before it goes in
2. Carry it at least 3 m from where you fuelled, set it down with the chain touching nothing
3. Chain brake on: push the hand guard forward
4. Hold the trigger lockout and trigger, set the lever to cold start (full choke)
5. Pull slowly until it engages, then a brisk pull; don't pull the rope all the way out
6. Pull until the engine pops once (usually 3 to 4 pulls)
7. At the pop, the lever up one notch to warm start
8. Pull again: it runs. Blip the throttle and the lever jumps to run
9. Chain brake off (guard back), then the throttle

Full choke lets in mostly fuel, which a cold engine needs to fire once. After that it needs air: more pulls on full choke wet the spark plug and it won't start at all. The common habit is to keep pulling on full choke until it runs; the maker's manual says to switch to warm start at the first pop, and the film follows the manual. Already flooded? The manual's fix: lever to stop, take the plug out and dry it, crank a few times, plug back in, then start on warm start even if the engine is cold.

Shown on a generic small two-stroke chainsaw, in the class of a STIHL MS 170 or MS 180; the saw is our own drawing.

Which machine should we do next?

Sources: STIHL MS 170 / MS 180 instruction manual (Fuel; Starting / Stopping the Engine; safety: 3 m from where it was refuelled); a STIHL dealer's starting guide (stihlshop.co.nz, 3 to 4 pulls on full choke).
Sounds: Freesound CC0 (kyles, Stefan021, t-man95, prpl.jlyfsh, gecop).