The Two-Stroke Is Coming Back. Here's Why It Almost Died

For fifty years, the two-stroke engine put the world on wheels. Scooters, mopeds, chainsaws, outboard motors, Grand Prix bikes. Then, almost overnight, it was gone. In this video: how a two-stroke works with only three moving parts, why it ruled the racetrack, why it was so dirty, how emissions rules pushed it out, and how fuel injection is bringing it back. Want to see each part moving in 3D? Watch the series: Part 1 · Why two-strokes are so simple:    • Why Two-Strokes Are So Simple (Part 1)   Part 2 · The fat pipe:    • Why Two-Strokes Have This Weird Fat Pipe (...   Part 3 · Why it runs upside down:    • Why This Engine Runs Upside Down (Part 3)   Part 4 · The power valve:    • How Two-Strokes Hit the Powerband (Part 4)   0:00 Intro 0:37 The simplest engine 1:39 The golden age 2:46 King of the racetrack 4:12 The dirty secret 5:14 The disappearance 6:09 The comeback 7:20 Simple, at a price Music: YouTube Audio Library (True Crime Documentary and Chill · Rod Kim, Twinkle · The Grey Room / Density & Time, No Rush · Dyalla, A Stroll Alone · Everet Almond) Stock footage: Pexels Photos via Wikimedia Commons: Piaggio Ciao · Henry91 · public domain Piaggio Ciao red · Fredrik Vogel · CC BY 2.0 Piaggio Ciao 50cc · CC0 Puch Maxi Special · Paolo2710 · CC BY-SA 3.0 Puch Supermaxi · Christoph Waghubinger (Lewenstein) · CC BY-SA 4.0 Tomos moped · Prolete · CC0 Kreidler Florett · Tim S Nhoj · CC0 Yamaha RD350 · Akibell · CC BY-SA 4.0 Yamaha RD400 · Schreiberling58 · CC BY-SA 3.0 1995 Honda NSR500 · Box Repsol · CC BY 2.0 Honda NSR500 engine · Morio · CC BY-SA 3.0 Yamaha YZR500 (1980) · AlbertoSossella · CC BY-SA 4.0 Suzuki RG500 MK5 · Nic Redhead · CC BY-SA 2.0 Hekelingen 1962 · Jan van den Berg / Streekarchief Voorne-Putten · CC BY-SA 4.0 1951 Mercury Super 10 · Sidcraft · public domain #twostroke #2stroke #engineering