Hello Dunz:

Welcome to the HUBB community.

For a trip of the distance you are planning (north end of Morocco down to Mauritania) you are going to need a new set of tires at some point during your journey.

See this post I made a few years back for information about how to get motorcycle tires in Morocco: Awesome Service from MotoPlus, Casablanca. It would probably be prudent for you to write MotoPlus well before your trip to confirm that they have tires in the size you need.

Big, expensive, "first world" motorcycles like the KLR 650 are extremely rare in less affluent countries such as the three you mention. This means that it's difficult to find parts for them, although you will have no difficulty finding shops who can work on the motorcycle (change tires, make repairs if you have the parts, etc.). So do be sure to carry out all necessary preventative maintenance before you leave on your trip.

If you have any doubt about how much life is left in your chain, sprockets, brake pads, etc. get those parts replaced before you begin your trip.

Based on my own experience riding down to the Western Sahara / Mauritania border, settlements & services (fuel, water, food, etc.) are few and far between once you get south of Laayoune. I suggest you obtain a 'Camelbak' water bladder for your own hydration, and don't ride past any gas stations if you have less than half a tank of fuel remaining. The village of Dhakla, about two-thirds of the way down the coast of Western Sahara, is quite tourist-oriented and has a lot of services. You might want to plan on taking a few days rest there before setting off towards the Mauritania border crossing.

Michael