The question “stroke or smoke” might seem like choosing out of ways to die, but for motorcycle riders it’s asking the preference out of the two methods of combustion. “Stroke” refers to four-stroke engines, now the dominant technology while “smoke” is two-stroke, nicknamed as such because of the plumes of blue smoke the engines produce as a result of the burning of oil along with petrol.
Beginning in the 1980s and 1990s, two-stroke engines were phased out in favour of cleaner four-strokes, the purge culminating in the establishment of the MotoGP Grand Prix class in 2002, which saw 990cc four-strokes competing (and dominating) the older 500cc two-strokes. By 2003, no two-stroke GP machines were on the grid and public two-stroke motorcycles were limited to farm and off-road equipment.
That has largely been the case since but, despite the emissions issues, two-stroke tech still has merits. For example, power is produced with every rotation of the crank, whereas four-stroke engines produce power only every second rotation. Kawasaki is rumoured to be working on a supercharged two-stroke engine that could become a type of generator for a hybrid system as, if operated within a set RPM window, two-strokes can run quite cleanly.
Kawasaki isn’t the only one working on two-stroke tech, either. A man from Australia named Basil van Rooyen has designed a new type of engine called the “Crankcase Independent Two-Stroke” (CITS) which apparently meets the latest emissions regulations. The CITS avoids total loss lubrication, which means oil isn’t burnt along with petrol during combustion.
Read more: Two-stroke motorcycles might be coming back