Scooterwest has this:
https://www.scooterwest.com/dr-pulley-variator-sliding-weights-21-x-17-9-5g-13-0g-dp21x17.html
Which says:
* These are lighter than stock and can cause the belt to ride too high rubbing the engine case and the hitting the rev-limiter (cutting power to the motor). We recommend installing an extra spacer washer between the two front variator halves (see part number 434885).
I read a lot about this on the forum here, seems the opinions are mixed. Is this a thing? The extra washer is a good idea?
I'm thinking about going with the 10.5g. I want to get better off the line acceleration, totally don't need more top speed. 60mph is more than fast enough for my scooter.