
What sort of mileage can you expect from a superbike engine when used enthusiastically?
Are we talking 10,000 miles tops, or ten times that??
It would put me off buying a bike engine with 30,000 on the clock if I knew it would need a 2 grand rebuild in 5,000 miles time, if ya know what i
mean...
Ed.
unless it is alot cheaper i would avoid and engine with that sort of mileage when there are so many engines around with very few miles on them.
if the engine dies or is very warn out it would probably be cheaper to get another one rather than totally overhauling it.
bike engine should last several 10,000 miles and i have heard of r1s doing more than 100,000 if looked after properly but only if serviced religiously
and with hige mileage bikes that could mean more than once a year whcih doesnt always get done whereas the person who only does 3,000 a year is likely
to get it serviced more often.
2 grand rebuild? Only if you're going for Carillo rods, cheeky cams, serious head work and a set of flatslides!!! 

Speaking from personal experience, if your bike engine goes pop (especialy a modern one) buy another one that works rather than trying to fix it -
it'll probably work out no more expensive and you'll save yourself LOADS of grief in the process.
Personaly I wouldn't buy one that had done much more than 10k - but then I have had some very bad experiences with bike engines 
Engine would not be your worry - gearbox may be the weakest link - depending on engine choice. For £2000 you're better off having an additional engine as a backup...
I'm told by an ex-Blackbird owning mate of mine that a guy on one of the Blackbird forums has done 250,000 on his!
God knows how much is original though!
Cheers,
James
JB7 has done something like 40-odd thousand miles in his Blackbird Westie (without a dry sump) and it has had some serious hammer! He doesn't use
it on the track though as he has a BEC single seater which he hillclimbs.....
If you look after your motor it'll serve you well. Use decent oil, let it warm up and do occasionally give it a good caning and you'll get
several 10's of thousands of miles out of it.
Yes, you do hear of failures but it tends to be down to either neglect, the user (changing down intead of up etc.) or just damn bad luck!
It could be worse - you could have a K-series! 