Fitting a big bore kit does not always give the expected increased top end speed, it certainly improves acceleration well but not top end speed, Why?
This often down the short gear ratios on your scooter, so if you find this is the case, the only way to combat this is by changing the gears to new longer ones.
Here we have alonger version of the gears from well known perfomrance manufacturer Naraku, these gears are longer by 20% from the original (15/37 teeth) which will provide higher top end speed without loosing power on acceleration.
These gears fit to all Chinese 125 and 150cc GY6 engines (152/157QMI).
Please note: There are variants within the imported Chinese scooters so we would seriously recommend you remove the old gears and ensure count the number of teeth prior to purchase.