Dr Pully makes a Variator for the GY6 lets give it a shot!
High Quality, High Performance variator from Dr. Pulley. This is a great upgrade for your bone stock or high performance engine.
Variator kit includes, Back Plate with spacers, Drive Face, Pulley, Pulley Spacers, and Drive Boss.
Pair these with Dr Pulley Sliders for the best performance you can get out of your Dr Pulley Variator.