The Yamaha MT-09 is a street motorcycle of the MT series with an 847–889 cc (51.7–54.3 cu in) liquid-cooled four-stroke 12-valve DOHC inline-three engine with crossplane crankshaft and a lightweight cast alloy frame. For 2018, the bike is now designated MT-09 in all markets.
The MT-09 competes against the Triumph Street Triple, Kawasaki Z900, and MV Agusta Brutale 800. It is intended to restore Yamaha’s fortunes, as the factory has in recent years lost its reputation for innovation. The MT-09’s product manager, Shun Miyazawa, said Yamaha had considered parallel-twins, inline-threes, inline-fours, and V-twins, but that the inline-three gave the “best solution” of power, torque, and low weight. Comparing the MT-09 to the Street Triple, he said the Triumph was a streetfighter, but the Yamaha was a “roadster motard”.
Both the frame and the double-sided swingarm are made of lightweight alloy, which are cast in two pieces. The frame castings are bolted together at the headstock and at the rear, but the swingarm parts are welded together. The MT-09 is the first Yamaha motorcycle since the XS750 and XS850 to be powered by inline-three engines. Both are shaft-driven motorcycles produced from 1976 to 1981.
In 2017, the MT-09 was updated with fully adjustable suspension, traction control, antilock brakes, slipper clutch, LED headlights, and updated styling.
In October 2020, the MT-09 received the second update with a larger 890 cc (54 cu in) engine.