I was always curious why so many people say the NMAX has a lot of power for a 150cc engine. So i did a little research and found about the VVA technology. VVA stands for Variable Valve Actuation. This means that the cam profiles changes when the engine is at higher rpms. This acts like Honda Civic VTEC but only for motorcycle.
Analogy:So from stage 1 cam, when engine reaches 6000rpm the cams change to stage 2.
Cam profile is very important in the engine since this will dictate how your engine will react at certain speeds. You might have a cam for low-mid power or you can have mid-high power. But you can’t have both. You always have to compromise.
Knowing this, Yamaha included the VVA(Variable Valve Actuations) technology in their new Nmax engines. So you can have low-mid power at low rpm and mid-high power to high rpms.
This is Yamaha Nmax Camshaft. 2 intake lobes(1 for low rpm and the other for high rpm) and 1 exhaust lobe.
How it works:
1. When the engine is at 0 RPM to 6000 RPM the low cam is at work.
2. When Engine is at 6000rpm and above the actuator pushes that pin and the rocker arm will now follow the high cam. Lifting the intake valves another 2mm from the low cam distance.
3. When the engine goes below 6000rpm again the actuator disengages, releasing the pin and the rocker arm follows the low cam again.
Please see the video Animation:
Actual video of VVA(Variable Valve Actuations) in action:
The Yamaha Aerox will have the same technology as the Yamaha Nmax