How to de-restrict a 50cc scooter

Updated April 17, 2017

Even when a 50cc scooter is in perfect working order, its top speed is often well below that of other vehicles on the road. This can make driving a scooter a frustrating and potentially dangerous endeavour. To increase the speed of your scooter, there are many aftermarket add-ons you can purchase and install. A cheaper and easier method of improving your scooter's speed, however, is to de-restrict its variator. De-restricting your 50cc scooter's variator requires you to remove a restricting washer from the variator or pulley system of the scooter.

Remove your scooter's kick stand by pulling the pin on the inside of the kick stand out completely and then pulling the kick stand off the variator box. The kick stand and variator box are on the left side of the scooter.

Loosen the two 10mm bolts holding down the covering of the intake box using a 5mm Allen key wrench.

Remove the six bolts holding on the lid of the variator case using an 8mm socket. Three of the bolts for the case on are the top of the case and three are on the bottom.

Squeeze together the mechanisms of each of the two pulleys, front and back, as if you are squeezing together a sandwich. This will loosen the pulley wheels, allowing you to work in the pulley system with greater ease.

Lock the front pulley wheel in place using a large strap wrench. Put the looped strap of the wrench around the pulley wheel, tighten it and wedge the handle of the pulley in place under the rear pulley. This will prevent the pulley wheel from turning as you unscrew the centre bolt holding it in place.

Remove the bolt holding down the faceplate of the front pulley wheel with an 8mm socket. Use a reverse or upside down grip while standing over the scooter with your head facing the rear of the scooter to crack the bolt. Pull up on the ratchet (counterclockwise on the bolt) to crack it and remove it.

Pull the three pieces off the faceplate of the front pulley wheel. The three pieces are the nut you just cracked, a washer spacing the top of the nut and a starter piece that mates the scooter's starter engine to the pulley system. Keep these pieces together.

Pull the faceplate off the front pulley wheel, revealing the pulley belt and rod.

Remove the restricting washer on the pulley rod.

Reassemble the variator's box in reverse order.


De-restricting a scooter could increase your scooter's top speed past your state's specified speed restrictions for 50cc scooters. Check with your DMV about your state's specific scooter operation laws or about re-registering your scooter as a motorcycle. Re-registering your scooter will require you to obtain an M-class license.

Things You'll Need

  • Strap wrench
  • 5mm Allen key wrench
  • Socket wrench
  • 8mm socket
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About the Author

Samuel Hamilton has been writing since 2002. His work has appeared in “The Penn,” “The Antithesis,” “New Growth Arts Review" and “Deek” magazine. Hamilton holds a Master of Arts in English education from the University of Pittsburgh, and a Master of Arts in composition from the University of Florida.