Flywheel Puller for gy6 50 125cc GY6 4-stroke engines Kymco 4-stroke engines The flywheel puller is used to remove the alternator rotor and is necessary when working on the alternator or any parts that sit below or when replacing the crankshaft or its bearings. The Naraku flywheel puller's body is screwed into the threads on the rotor, then the centre bolt is tightened to exert steady, uniform pressure to pull the rotor off the crankshaft. In the casr that this should this not work, you can try to carefully hit the centre bolt with a hammer. There are not many special tools you need to work on your scooter's engine, but the Naraku flywheel puller is one tool you should definitely have in your toolbox.