These problems have perplexed me for some time now. I finally chucked another starter in and that seems to be the issue for me. However, I noted that you've done that. In fact, you've done most of the things that come to mind. Therefore, I would look at round two:

1. If the NSS was recently replaced, it may have jarred slightly out of position.

2. My starter was only a year old (on a rebuild) but I discovered that the first guy didn't re-do the windings.

I had people pull start me until I reached the point of embarassment one too many times. Finally starting replacing stuff rapidly and found that the starter was the issue.

Don

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