Thanks for the feedback. To further clarify, it doesn't appear to be electrical since the starter continues to "spin" if you hold the key in the start position. Its more like something you would find in a car starter with a bad Bendix. It just doesn't stay engaged long enough to turn the crank.
I recently purchased a slightly used HD5 and having an intermittent issue with the starter. When trying to start, the starter engages then immediately disengages. It acts like a failing bendix. I replaced the starter with an aftermarket unit and still had the problem so I took it to my dealer...