It only got mentioned about 2times. Someday you will pick up a chick though hopefully you won't try and impress her with your mechanical knowledge.
Why is there any need for mechanical knowledge to work on a harley? The engine is the most basic IC engine made. Two cylinders, one carburetor, push rods, four valves. Suck, squeeze, bang, blow. That's it.
Try mapping a new DCI fuel injection if you want to test your knowledge.