Secrets of the new Yamaha Tracer 9 engine

the Yamaha Tracer 9 2021Like its predecessors, it is equipped with a forward-facing three-cylinder engine. It’s a new unit shared with MT-09 2021, similar in some features to the feature it replaces. We are referring, for example, to the chain-actuated dual upper camshaft timing system with a thin shoe tensioner; to the four valves per cylinder; for forged pistons in tandem with connecting rods with separation of the cap and half of the head resulting from breakage; with a compression ratio of 11.5:1; to the crankshaft with crank pins corresponding to 120 ° (the order of bursts is uniform, every 240 ° of rotation of the shaft), together with the crankshaft to dampen vibrations; To direct the installed cylinders at the offset (forward) of the crankshaft.

Macro differences with the unit previously used on the Tracer 900 They affect everything else, starting with the assimilation system. The three channels have a custom length and shape, in favor of both conduction and sound: the house’s music department has contributed to the development of the intake and exhaust systems to ensure the engine’s ‘sound’ is as beautiful as it can be. The throttle bodies are now complete by wire and have the injectors in conventional position (on the old engine they were placed directly into the head). According to the manufacturer, this change significantly improves engine efficiency, reducing consumption by 9% (WMTC cycle). Then there are the new bore and stroke sizes ranging from 78 x 59.1 mm to 78 x 62.1 mm. The displacement increases accordingly from 847 cc to 890 cc. The crankshaft has a 15% higher mass of inertia, the gearbox is “longer” first and second: the ratios go from 2667 (40/15) in the first and 2 (38/19) in the second to 2571 (36/14) in the first and 1947 (37/19) per second. The selector forks have been redesigned and the clutch, with multiple discs, in the oil bath, with slipper, is new. The initial (1.681) and final (2.813) transmission ratios do not change.

Compared to the past, education (Euro 5) and performance have improved: Maximum power measured at the wheel ranges from 104.5 hp at 10100 rpm to 108.6 hp at 10,000 rpm; Maximum torque from 80.9 Nm at 8200 rpm to 85.7 Nm at 7000 rpm.