Towards the late 1960s Yamaha was winning grand prix (GP) races with their factory air-cooled two-stroke racing motorcycles, easily beating four-stroke machines with larger displacements.
In 1969 Yamaha introduced production racing motorcycles based on their GP racers but available over the counter to customers. These proved very popular in senior and open class racing. This was a clever way of marketing their brand with the ordinary man on the street being able to access a GP replica for under $2,000 (Sh13,800 at 1973 prices).
