First check tire pressure and oil level before changing the weights but yeah I would guess the weights are the culprit here like you said.
The reason I say check tire pressure and oil first is because under inflated tires can reduce speed and overfilled oil can bog down your speed as well.
Mine when I bought it new from the dealer in May was wayyy overfilled with oil and after searching online I have found that this experience is very common with this bike.
I’d reccomend getting this kit then find what works for your body weight and local topography and get the DR Pulley version of the correct weights. Will save ya a lot of money
> do the weights matter if I get some stage six one or some generic ones
Unless you are racing a decent set (of 6) is probably $10 or you can go fancy and get $15 ones. NCY weights are more like $20 but I'd consider that high end fancy schmancy.
It's worth noting that your weights should be inspected/changed every 1000 or so miles anyway, so if you bought used it would probably be good to go ahead and change them. Here is a very good GY6 service manual too BTW
You will likely also (arguably) need a torque wrench for reassembling the transmission and a clutch holder. If you don't have these you can get by using other methods or a strap wrench
Its worth noting there are also sliders that you can use instead of rollers. If it makes any difference probably has to do with the slope in your variator and the design of the slider. There are many, many different combinations.
I found one source that says:
> "for every .5 grams heavier , it seems as if you loose about 250 rpms or so. Maybe a little less. "
but I cannot say if that is accurate or not.
You might also be able to change your variator to get a little bit more difference as well. As with changing weights its something some people seem to swear by and others say does nothing. Either way companies like NCY make nice parts that may be lighter and generate less/dissapate more heat, last longer, and offer a smoother ride than stock parts. If you go this route you can usually do it one piece at a time.
I'm still pretty new to all this though :-O so by all means if someone sees I said something inaccurate let me know!