I have a Centra Compensator, flywheel and clutch assembly sitting on my work bench. The nut that holds the compensator to the crank loosened and I kept the old parts after everything was replaced. The flywheel is steel and has very little mass. It provides the friction surface for the clutch plate and teeth for the starter to engage but not much else. It probably weighs a quarter of what a BMW opposed twin motorcycle flywheel weighs. In my humble opinion, most of what I would attribute to flywheel function is the mass of the pressure plate.
The 2015 pressure plate has much stronger springs than the 2013 unit it replaced.
