Unless something is not adjusted properly or broken, the 2 speed should shift into second when the engine reaches a certain speed. If it does not shift, use a 2mm Allen wrench to adjust the shift point set screws counterclockwise. Turn the set screw 1/4 turn at a time and make a test run to see if the car shifts into second. If it does not, turn the set screw 1/4 turn more and try again. Make sure not to touch the center set screw! If you look on the two speed gearbox you will see a small 5mm hole on the smaller gear. If you rotate this hole it will give access to the two shift screws. There is one on each side of the gear.