Hello I have an Aprillia sr motard It has front malossi variator with 3.5 rollers . Race 50cc polini cylinder .stock carb and yasuni 21 exhaust. I have lowered the rollers but the acceleration is still low what else can I do to the back clutch to help with the acceleration (what color springs should I get?) Thanks
Clutch springs don't help with acceleration, they engage at different rpms to allow a better initial pull away. Your scooter needs to nearly reach its power band rpms and as it does then you want the the clutch to engage , wheel turns and max power hits. Buy a pack of springs that come in three sizes. If your clutch is engaging too early, at low revs, then fit the next size spring. Look at the springs and you will see they have different number of coils and different thickness wires. Less coils and thicker wire is a stronger spring so will engage later. Too strong and it won't open so your bike will rev high and go nowhere.
Just to back up the above. 1, You mention your roller weights so you’ve probably fitted them yourself. They’re not changed to really alter acceleration or top speed but to activate your variator at your engines peak power band. Good acceleration and top speed should come once you’ve found the right weight. Don’t change them to gain one or the other as your not actually improving anything by doing that. If you change them and it improved over all they where wrong before. 2, Yes although the springs are not for acceleration altering the bite point of the clutch with slightly stiffer springs will give you potentially better acceleration as the clutch won’t engage till your revs have built up higher and closer to your power band. I had this when tuning my LX. It was powerful and fast through every stage except initial launch. I got the Jasil spring set and went for the middle strength out of the 3, and boom it was sorted.
