There are lots of ideas about what Dr Pulley sliders do, how they work, what they can do, and can't do.
Two good sources for Dr Pulley information in the USA are BuggyPartsNW and GoKartsUSA.https://www.buggypartsnw.com/index.php/dr-pulley-products/dr-pulley-slider-weightshttps://gokartsusa.com/gy6150performancesliderweights-2.aspxBelow is a copy of what both have to say about Dr Pulley sliders.
Choosing the proper weight -
when compared to your stock roller weight:Lighter weights will give a lot more climbing power at the cost of some top end speed. Cruising speed RPMs will likely increase as well.
Middle range weights will give improved low end power, climbing, and acceleration versus stock weights. Top speed should be similar to stock weights, and RPMs will be similar to the stock weights
Heavier weights retain (or slightly improve) existing top speed with the possible expense of climbing ability - but are great for reducing top speed RPMs for better gas mileage.
I hope this clears up some of the fog about how these Dr P sliders work - and what they will do in your scooter, kart of 4-wheeler.
(
Personal Examples - While I have no personal experience with the top speed of any of the 4 scooters I've owned - I will relate this > my Burgman 400 had plenty of power, but I wanted to reduce highway cruising RPM's. I installed a heavier DrP slider weight and it dropped my RPM's by 1,000 at 75>80mph. I went with 1gm lighter sliders in my LIKE200i - but it increased my cruising RPM's too much, so I removed them.)