Perhaps more helpfully...
when it comes to insurance, make sure you're covered for riding a motorcycle (some insurance policies classify anything bigger than a 125cc as a dangerous activity, and won't provide medical cover). Others only cover you where you start the trip in the country where the policy is underwritten (can't think why they do this, but hey), so if you're already in Egypt make sure the insurance doesn't have this kind of clause.
Don't know tuppence about documents for the bike. Although articles like this (https://www.adventurebikerider.com/article/a-sudan-change-of-circumstance/) are a good read, they're short on details like that (although they do mention a carnet). But perhaps you could get in touch with the authors and ask.