Meanwhile, on the R90S, Mark turns on his fuel taps, pushes down the choke lever on the left side of the engine cases, and merely hits the starter button. No gasoline is slathered. The engine fires almost imme-diately with a rocking motion, and the pumper Dell’Orto carbs let it idle with a slightly hollow and metallic exhaust note. The left-shifting gearbox (one down and four up in the modern mode) accepts first with a reluctant grunch and is then slightly notchy on all shifts that follow. It’s one of the enduring mysteries of the late 20th Century that BMW, builder of long-lived, precision engines, didn’t produce a truly slick gearbox in that era. It works okay but never endears itself to your left toe.