Yamaha has revamped its latest YZF-R125 to look and feel more like a scaled down MotoGP racer. The company, a leader in the sports 125cc market for a number of years, constantly hones its tiny zappers, but always within the power limits established by national authorities around the world.
In Europe, for example, 125cc bikes of any kind are not allowed to have more than 15 horsepower. But within this power limit, Yamaha has created a lovely little screamer that’s dressed in a radically redesigned fairing inspired by that of the celebrated YZF-R6 Supersport racer. Double headlights flank the air scoop, which is now located on the nose of the fairing for maximum efficiency.
The engine has been upgraded, too. Given the power limits, the lively, liquid-cooled sohc four valver has been designed with undersquare measurements (52mm bore x 58.6mm stroke) to obtain the fattest possible torque curve at mid rpm. Additionally, the undersquare measurements allow a very clean combustion chamber design and a flat piston top, along with a compression ratio of 11.2:1. This ensures good midrange response, thanks also to the completely renewed integrated injection-ignition system, which further aids fuel efficiency.
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