There's a 1999 model in Ireland with 130000, still going, cant confirm if it was miles or kilometres unfortunately. Hadnt had valve clearances checked apparently(!)
Don't believe the dealers bullsh1t - they've created the idea that an engine is finished by 20k.....do regular oil changes and it'll last 10 times that amount.
According to Bike magazine, there's a middleweight inline 4 on the uk's roads still running with over 500000 miles, and just by sticking to a normal maintenance schedule. Warm your engine before you cane it & it'll last until you're bored with it....and it be still be running