The 2010 Yamaha Roadliner promises high levels of performance. And it’s not hard to see why. The cruiser features 113-cubic-inch air-cooled 48-degree, four valves per cylinder motor, a V-twin power plant that produces massive torque and a class leading acceleration. Twin-bore downdraft electronic fuel injection ensures optimum engine efficiency and throttle response in all climatic conditions. The large size of the valves helps increase the engine horsepower and torque. The four-valve cylinder heads ensure optimal breathing efficiency for great power delivery at all rpms. The two spark plugs per cylinder allow complete combustion for maximum power output. The valve train has been specifically designed to include short design intake and exhaust rocker arms that reduce inertia during high rpm use. Exhaust Ultimate Power valve (EXUP) inside the two-into-one exhaust system boosts torque in the 2500-3000 rpm range. Ceramic composite-plated cylinders ensure uniform heat dissipation and help to reduce weight and friction, and boost the cylinder service life.