Yamaha QT50

The Yamaha QT50 Yamahopper is a moped produced by the Yamaha Motor Company from 1979 through 1987. The 50 in the name is derived from the 50cc engine displacement. QT50s were popular in the late 1970s and 1980s because of their ease of use and maintenance, exceptional gas mileage, and legality in most U.S. states among pre-driving-age teenagers. QT50s and other mopeds are enjoying a resurgence in popularity due to their nostalgic appeal.

The QT50 is actually in a class of its own - skeletal, almost insect-like in appearance, the Yamahopper is not really a scooter (QT50 has no fairing, sports footpegs rather than footboards, and its 2-stroke reed valve engine is slung beneath the monotube frame motorcycle-style.) More closely resembling contemporary mopeds, but without the bicycle pedals typical to the class, the QT50's ultralight, low-maintenance design was a fresh take on individual, cheap mass-transport, offering incredible reliability and durability, cheap initial cost and minimal operatng expense, together with the freedom to take one's own path where the rider chooses as opposed to using trams, buses or other non-individual forms of urban mass-transit. Ideally suited to darting through or around inner-city traffic snarls at speeds up to approximately 28-30 mph, the QT50 incorporated many notable features and innovations.

The compact, weatherproof drivetrain of the Yamahopper resembles somewhat a minimalist version of the enclosed shaft drivetrains of most BMW motorcycles. Its simple, maintenance-free shaft-drive contained in the single-sided swingarm eliminated chain maintenance, safety and wear concerns as well as weather wear factors and contributed to the legendary durabilty and ease of use of these tiny motorbikes. The drive unit also incorporates a traditional centrifugal clutch and variable-rate automatic transmission that is virtually foolproofand and nearly indestructible in normal or even heavy use. The novel driveshaft setup also made wheel changes a 30-second matter of removing a single bolt and brake cable.Other noteworhty features of the QT50 were its quirky chanrging and ignition system incorporating a tiny 6-volt battery and alternator. The innovative system eased cold starting - when the key was placed in the "start" position,the ignition supplied a stronger than normal spark for initial starting, but did not allow the engine to rev so as to avoid burning the piston. Once kicked to life with the reverse-mounted, left-side kickstart lever, the key is turned to "run" and the engine is able to rev freely. The QT50 can get upwards of 150 miles per gallon.