Hi, I don´t know, if you can get a visa for Iran or not with an American passport (or maybe that´s why you´re actually planning such a detour?)... but going thru Egypt etc. to UAE, I would not assume it´s going to be easy either. And I´d probably keep away from Yemen for now. Some of my countrymen were kidnapped in Sanaa just a few weeks ago, remains unclear, who is holding them.
And how about the visa for Pakistan then? If you can get it, then that should probably open the route via the Stans north side of Afghanistan, thru China to North Pakistan, and onwards to India. The China bit isn´t exactly easy or cheap, and some areas in Pakistan are dodgy, but a few travellers go that way each year, so it seems like a do-able way to India. Won´t need to freight the bike on that route either.