This off-set flywheel timing key allows you to advance your ignition timing without modifying your stator or cases. Our dynamometer test vary from engine size and application to application but generally we have shown an increase from one to four horsepower on stock engines and as much as 8 horsepower on our full mod motors by using our advanced timing key. Increased ignition timing allows your engine to build more cylinder pressure which increases your horsepower. For low elevation applications we encourage you to use higher octane fuel to prevent detonation while trail riding. We offer two different sizes and two different offsets. If you are not sure which one you need you can call our tech line for assistance 1.888.224.5005.