Ever been to a race with modified Go-Peds? Then you've probably seen a stock flywheel come apart, ruining a racer's day. Modified engines rev up a lot faster than the heavy stock cast flywheel was ever designed for, and the flywheel c an literally fly apart! That's dangerous for the racer, the racers around him, and folks in the crowd. That's why the MSD engineers designed a billet aluminum flywheel to replace the stock cast flywheel. And they came out with a real winner! The MSD flywheel is made from one-piece 6061-T6 billet aluminum, turned out on a CNC machine to the exacting specs you would expect from MSD. It's a lot lighter than a stock flywheel, and that means your goped engine is going to be able to rev up quicker. Take a look at the difference in weight between the heavy stock flywheel and the lightweight MSD Billet Flywheel, it's an eye-opener! Since it's made from one-piece billet aluminum (and not cast) you've got a flywheel that 's stronger, balanced better, and allows the engine to rev up quicker. That's a win-win situation from MSD! An adapter, the Pull-Starter Hub bolts onto the MSD Billet Aluminum flywheel with just two bolts, & allows you to use the stock pull starter.