The flywheel’s job is not just to transfer engine motion to the clutch and transmission. What the flywheel also does is act as a balancing mechanism for non-internally balanced engines in combination with an off-balanced engine dampener. Now, here is where you have to be careful; some engines are semi balanced and others are internally balanced. Semi-balanced engines means the flywheel is off balance, but the crank dampener is neutral. Internally balanced engines require a neutral balance flywheel and crank dampener. I’ve experienced cases where the balance of the engine was off and engine parts start wanting to shake their way out.