You posted on another thread that a magnet came off the flywheel right? If its still off so is the balance of the flywheel. The flywheel was balanced when new and without the magnet weight the flywheel is off balance. If you have your tires on your car balanced and one of the weights comes off, your wheel/tire is now out of balance and you car vibrates. But if you replaced the flywheel with the missing magnet with a different one then you have another problem. Did you do that? Correction; If you replace the flywheel with a good flywheel and you still have a vibration then you have another problem. ;End Correction