At this point in their lives mate, the kms on the clock are getting less and less likely to mean anything, engines may have been swapped, clocks may have been swapped... Look for smoke on cold start or when revving, or ideally get a compression check done, that will tell you a lot more about the engine than the number of kms on the clock will.
Also, as per what Cerberus said, check for fork oil around the fork seals, check for good chain maintenance, check for all the sort of stuff which will cost you as much as engine repairs but is -much- easier to look for.