shud i use 88 jet and drill the air box
Never tried that so I can't advise.
As for the rollers, a lot will be a matter of personal taste and driving conditions.
Lighter rollers give you more pickup off the start and are good for hills so are useful for people who do a lot of stop and go or face hills. How much more pickup you want and the types of hills you climb will factor into how much lighter you want to go.
So the weight will depend on how you like your scoot to respond, weight of the driver, etc.
Usually you need to do some experimenting and see what works best for you. 6gm weights wouldn't make that much difference from your stock 6.5 gm weights so you might be disappointed with them. Or, they might work great for you. As I said, you don't know until you try.
You can buy roller kits that have a variety of weights to test out. Once you've figured out what weight works best, I'd just buy some Dr. Pulley sliders in that weight and use them.
