I just finish crossing Africa two-up on a 2009 F800GS.
The bike had approx. 10,000kms when we started and we did 20,000kms on it across 10 countries (South Africa to Egypt).

Around 20,000kms the engine started leaking oil (a common problem with all/most 800GS apparently) and it got fix at Jungle Junction in Kenya.

The bike is not ideal for riding 2-up off road as the tank is in the back and makes it unconfortable for the pillion while standing up.

After the trip I took the bike to the dealership and they asked me for 3,000 USD just in spare parts to fix it. The bike is still running fine but it needs a lot of love. It's an expensive bike to travel with but I guess all GS are.

I'm planning to keep the bike and do some more long distance riding on it.

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Nicaragua Motorcycle Rental and Tours

I really wanted to like the F800GS and in the beginning I was really in love with it. But...

The engine needs to be very carefully warmed up, before using it hard! Some years ago I had bought a demo bike, just 750km on the clock. Soon realized that the engine sounds strange, compared to other bikes. I found quite a few documented cases in the internet of excessive piston/cylinder wear and when BMW after half a year of discussion finally opened up the engine, this was exactly the problem they discovered. Obviously the bike was mistreated before being really broken in and not warmed up sufficiently.

BMW installed a replacement engine, but this one leaked oil at the the head after only three months, another problem well documented, but never solved. If this kind of problem has been existing for years, I am expecting that a new replacement engine should not show it!

The whole story had then gone on for over 9 months and I was so disappointed of BMW quality (and the behaviour of the service department which had delayed the repair for 6 months!!!) that I sold it and got a 990 adventure.

I got rid of that later just because I wante to have a lighter bike and replace that one last fall with a 690 Enduro.

Hopefully rumors of a new KTM 900ccm engine will prove to be true and they make a F800GS competitor around it!