Absolutely no offense intended, Optik, but if you don't know what a flywheel weight is, and you ride a motoX machine (CR, KX, RM or YZ), then you probably will like the benefits of adding one.
I added an 11 oz. weight to my RM, and I love it! It makes the rider (ME) much less aprehensive to grab a handful of throttle, because there is no longer the uncontrolable (my word) burst of power that there used to be. It is very smooth.
Get one, they take about 10 minutes to install.:)