If you are using a K series Kohler, then after you have degreed the flywheel, found TDC and made your timing marks you can just adjust the timing by slightly moving the points on the bracket. There is an adjustment screw for that on the bracket. If the tractor drives off the flywheel then the last thing you want to do is use an offset key to adjust your timing. The key will fail sooner. With the command motors the aftermarket steel flywheels have an adjustment for the magnet location to bring your timing to where you want it.