The introduction of the Honda CB750 Four in 1969 was a tectonic shift in motorcycle history. With an inline-four OHC engine, electric start, front hydraulic disc brake, it was miles ahead of the what the British motorcycle industry could field at the time (one month earlier Triumph/BSA had introduced with great fanfare a triple with no electric start and drum brakes, slightly heavier and with 15% less power than the CB; to top it off the Triumph/BSA costed $1850 versus $1200 for the Honda).
According to the AMA's vice president for marketing, "At the dealership I went to, the sales trick was for them to stand a nickel on its edge on the engine cases with the thing running... If the carbs were in sync, even at idle, the nickel wouldn’t fall over."
Who would have said at that time that the trick was not new, it was used by Royal Enfield powered tractors,
"At 1800 r.p.m. a small cigarette lighter was placed upright on the bonnet and did not budge, ample proof of the lack of vibration"!