The following was published by BMW to highlight improvements in Gen 2.0 models, 2016 and later. What's most noticeable, viscerally, is 2016+ models take off faster and sound more like a BMW motorcycle.
No idea about Automatic Timing Chain Tensioner. They're all automatic. Major difference is mechanical or hydraulic, and hydraulic is better. If you have a Gen 1.0 model, 2012 - 2015, there is a recall on the Tensioner. You can check the VIN # with any BMW dealer to see if that work was done on your bike.
2016 ENHANCEMENTS TO BMW C 650 GT and BMW C 650 Sport.
New suspension and damping set-up for an ideal compromise between sport and comfort.
In addition to ABS, now also ASC is standard for maximum safety when accelerating.
Completely new, dynamic design for the C 650 Sport.
Detailed stylistic fine-tuning for the C 650 GT.
New silencer. The new exhaust system is made of stainless steel as before, but does not have a front silencer. Fitted only with a rear silencer, it now offers a particularly full and sonorous sound and dynamic new look.
New instrument dial design.
New handlebar trim elements with chrome applications.
New, higher-quality surfaces (graining effects).
Automatic daytime riding light.
Revised kinematics of the center stand for easier use.
New rider assistance system Side View Assist (SVA) for the C 650 GT.
New paint finishes for the C 650 Sport: Valencia Orange metallic matt, Light White non-metallic and Black Storm metallic.
New paint finishes for the C 650 GT: Black Storm metallic, Frozen Bronze metallic and Light White non-metallic.
TECHNOLOGY
New CVT set-up and revised clutch linings for more dynamic clutch engagement and a more spontaneous set-off response (faster off the line). Power transmission from directly integrated CVT (Continuously Variable Transmission) which underwent extensive adaptations for use in the new C 650 Sport and the new C 650 GT.
Softer springs and optimized clutch linings used in the centrifugal clutch.
Powerful 2-cylinder in-line engine with new set-up, optimized CVT and new exhaust system.
In order to achieve a low mounting position and therefore a low center of gravity, the engine has a cylinder bank that is tilted forward by 70 degrees. The characteristic sound and low level of vibration are due to the 90-degree crankpin offset, 270-degree ignition spacing and two counterbalance shafts powered by spur gears.
The sophisticated cooling concept to BMW Motorrad standards ensures optimum thermal balance in the 2-cylinder in-line engine. Here, coolant flows transversely through the cylinder head, entering at the front of the cylinder head on the hot exhaust side. The intensive cooling effect rapidly dissipates the heat precisely at the point of maximum thermal stress, thereby ensuring excellent temperature compensation. The aluminum radiator with plastic water containers and integrated thermostat has the same high-performance radiator network as is used in BMW motorcycles. Due to its high degree of efficiency and excellent air intake and through-flow, a relatively small surface is sufficient for operationally reliable heat dissipation in all conditions.
Carburation of the 4-valve engine with two overhead camshafts is taken care of by an electronic fuel injection system. Meanwhile oil is supplied by a dry sump system with a dual oil pump, and an efficient cooling concept ensures optimum thermal balance in the 2-cylinder engine. Engine mapping was redefined for use in the new C 650 Sport and the new C 650 GT with a view to satisfying the requirements of the EU4 pollutant class.
In addition to increased roller weights, the transmission ratio spread of the CVT has been increased from 2.42 to 2.95. The long CVT ratio is now 0.82 instead of 1.00. The gear reduction ratio between the CVT output shaft and driven shaft has been shortened from 2.72 to 3.28. In addition to a more spontaneous set-off response, this also makes for an increased top speed (180 rather than 175 km/h), or 111 mph).