Some additional information to compliment Tomek's post above, based on my own experience entering Tunisia with my Honda ST 1100 in March of 2020:

I took the ferry from Palermo, Italy to Tunis. Not a particularly long crossing, quite straightforward. Bring your own tie-down straps (ratchet straps) for the motorcycle. The ferry deckhands directed me to a large open area, away from other vehicles, where I could tie down my bike. They wanted to tie it down themselves, and it was obvious that they didn't know how to do it without damaging the motorcycle. After a little bit of discussion, they let me tie it down myself.

Port formalities after disembarking at Tunis were uneventful, but a bit time-consuming - about 90 minutes total. I was sent back and forth between a few different offices to get all the paperwork done. The officials were very courteous and very pleasant to deal with - not the slightest hint of a request for a bribe. They seemed genuinely happy to see a Canadian visitor with a Canadian-registered motorcycle coming to visit their country.

I could not find anywhere at the port to buy insurance, but this might have been because the ferry arrived at midnight. I spoke to the person who appeared to be the senior Customs official, and he told me to just ride to my hotel in downtown Tunis and to visit an insurance office the next morning before setting out on my travels.

It did take me quite a while to figure out how to get insurance for my foreign-registered moto - I explained that process in a post at this link: Tunisia Vehicle Insurance.

The "Authorization de Circulation pour un Vehicule Automobile" that the Customs folks gave me at the port entitled me to ride the motorcycle around in Tunisia for 3 months, which was the same length of time that the tourist visa stamped in my passport was good for (the visa was granted on arrival, no prior formalities were needed).

Unfortunately, about 2 weeks after I arrived in Tunisia, the COVID-19 pandemic exploded. I eventually left Tunisia on a direct flight Tunis to Canada, leaving the motorcycle behind in storage in Tunisia. Once again, the Customs folks were quite understanding about this pandemic problem and my need to leave the motorcycle behind in Tunisia when I left the country - they asked me to leave the registration papers (ownership) and the "Authorization de Circulation" document with them at the airport office, and told me to come and see them when I return after the pandemic to pick up the papers and the motorcycle. They didn't suggest there was any time limit for returning. I think that the Customs people understood that the primary purpose of all the paperwork relating to temporary importation of foreign vehicles was to prevent people from importing and selling vehicles, and by retaining the ownership document, they could be assured that I would not be selling the motorcycle during my absence from the country.

All in all, a pleasant & trouble-free (though a bit time-consuming) experience in all respects.

Michael