I have 1993 DR650 with 55000 km. No engine problems unless one counts the odd cold cranky kickstart nonstart.
I am on my second set of Kenda 270s and they last me 10,000 km of 50/50 pavement/gravel roads.
I did increase the rear sprocket by 6, 42 to 48 which is a 14% lower gearing and it makes first gear much more useable.
Rear shock and fork serviced at 40000km.
I live in Calgary and usually do 300km daytrips around this area and am available for rides Mon to Fri.
There are lots of roads that are posted as unmaintained and no exit, but are great for adventure riding.