YAMAHA RZV 500 R: THE LEGENDARY TWO-STROKES ENGINE
At the Tokyo salon in 1983, Yamaha introduced the RZV 500 R model. The V-engine architecture and the aluminium frame used were inspired by the Grand Prix model YZR500 - OW61 (which debuted to World Championship with Kenny Roberts in the 500 class).
The heart of the vehicle was a 499 cm³ four-stroke four-cylinder propeller driven by a six-speed gearbox. Capable of delivering the power of 87 hp, was able to push the RZV 500 R up to the maximum speed of 227 km/h.
The peculiarity of this engine was the use of the YPVS (Yamaha Power Valve System) exhaust valves that allowed to optimize the engine delivery curve at all engine speeds. This guaranteed performances comparable to those of the 750 cm³ models with a four-stroke engine. Particular were the four expansions: two of them were brought under the fairing, on the sides of the saddle, while the other two sprouted from the lower part until reaching the tail.
The frame was double beam and double closed cradle, it could be dismantled into rectangular steel tubes with a welded frame. The braking system consisted of two disc brakes.
The front panel was closed by a Kaiaba system with aluminium sheaths, at the rear by a swinging steel swingarm and an adjustable hydro-pneumatic single-piston with 5 preload positions.
Although this typology of engines, for marketing reasons, has stopped being so important after the massive diffusion of four-strokes engines, the Suzuki RG 500 Gamma and the Honda NS 400 R represented the highest level of two-stroke sports production.
Thanks to Valentina Zanola for the cooperation