A typical scooter uses a drive component called a variator. Instead of a geared transmission, variators use a single sliding, cone-shaped plate called an angle plate. As the RPMs increase, the angle plate slides outward and changes the size (and therefore the ratio) of the drive pulley. Roller weights affect the sliding action of the angle plate. Heavier weights allow a higher top speed but slow acceleration; lighter ones grant zippier acceleration but limit top speed. You may want to experiment with different weights to change the performance of your scooter. First, however, you must know what you have.
Remove the angle plate from the scooter's variator using the tools specific to your bike. The angle plate is a cone-shaped piece of metal located on the outer side (closest to you) of the pulley that is driven by the motor.
Remove the roller weights from the inside of the variator. Once the angle plate is off and no longer holding the weights in place, it should be simple to slip them off of their posts.
Determine the dimensions of the roller weights using a ruler or measuring tape and a scale. Size between brands and models can differ, but are always standard within the scope of a specific model. For example, if the roller weights are measured to be 15 millimetres by 12 millimetres, all other weights that fit your scooter will be this size, though they may have different gram values.
Compare your weights to the stock options in a scooter store. An alternative way of determining your scooter's roller weight size if you do not have an appropriate scale is to carry your weights into a dealer and heft them alongside those of known weights. This method is not as complicated as it sounds, given that an individual scooter has a narrow range of weight sizes that fit that particular model.