Yamaha YZ250: the 1974 Monocross motocross milestone
The 1974 Yamaha YZ250 helped bring Yamaha's Monocross rear-suspension concept into a production motocross motorcycle.
The suspension story behind a competition motorcycle
Why the 1974 machine matters
Yamaha's historical collection describes the 1974 YZ250M as a production motorcycle equipped with Monocross rear suspension. That is the point of this story: a specific model and a documented engineering milestone.
Monocross was not merely a marketing name. It represented a different arrangement for rear-wheel suspension from the twin-shock layouts familiar to many riders at the time.
The documented engine
Yamaha's original model entry lists an air-cooled two-stroke single-cylinder engine of 246 cm³ for the 1974 YZ250M. The same archive gives a factory output figure for that year.
Those figures belong to that specific historical machine. They should not be reused as the specification for a modern YZ250 or a different competition trim.
Chassis and rider feedback
In competition, suspension behaviour influences traction, rider control and how a motorcycle responds to rough ground. Engineering development depends on how a design performs under real racing conditions.
The significance of Monocross is best understood in that practical setting, alongside the engine and chassis changes that followed in later decades.
How to research a particular YZ250
A model name alone is not enough to verify a classic motocross bike. The production year, frame identification, engine details, suspension hardware and service history should all be checked.
AnyBike's model catalogue provides a starting point for that research, while source documents and an inspection establish the facts of an individual motorcycle.
Yamaha — Communication Plaza YZ250 historical collection
This is editorial motorcycle history, not a statement that stock is available, export eligible or approved for registration in a particular country.