A friend was wondering when reed valves were first used in a motorcycle. I know that they were invented by the founder of Mercury Marine in the 50s, and they were used in chain saws by the 1960s. I also know that the 1972 Yamaha DT2-MX was the first Japanese production model to have reed induction. But accessory reed blocks were already on the market at that point. So my question is, what (and when) was the very first reed valve motorcycle worldwide, including works racers, concept prototypes, etc.?