A Honda Dio's top speed is restricted by a small spacing washer placed on the front pulley rod inside your scooter's variator case. The variator case is located on the left side of your scooter below the seat. It is the flattened, cylindrical case to which the kickstand is attached. Destricting your Honda Dio scooter requires you to access this washer and remove it, thereby increasing your Dio's top speed.
Loosen the bolt attaching the kickstand to the variator box and pull it partially out to remove the kickstand from your scooter.
Unscrew and set aside the three bolts holding the plastic intake cover over your variator box.
Loosen each of the six bolts holding the metallic cover of the variator case. When each bolt is loosened, unscrew them completely, starting with the three bolts on the bottom of the case, then moving on to the three bolts on the top of the case. Set the cover and bolts aside.
Use an impact wrench to remove the center bolt holding down the front pulley wheel in your variator case. An impact wrench is an air-powered wrench that operates so quickly, it compensates for the fact that the bolt is connected to a spinning axle. Attempting to remove the bolt with a regular socket wrench will only turn the front pulley wheel.
Remove the front wheel from the variator case, revealing the front pulley rod.
Take the spacing washer off of the front pulley rod.
Reassemble the variator system, case and intake cover in reverse order. Ensure that each bolt is sufficiently tightened.
