my f4i has 40,000 miles on it. i doubt the previous owner did more than change the oil and some of the other fluids. $40 says the valves have never been touched since the factory. the thing runs perfectly.

my F2 had 58,000 miles on it when i sold it, and was running great when i did sell it. there was a R/R issue, but that's par for the course w/ those bikes.

I put 10,000 on the f4i myself and about 4000 on the F2.

 

Never buy a stunt bike...period. No matter how many miles they've got (or not got) on them, they're 99.9% more likely to be in bad shape over a bike that was used for communting with 5 times the mileage.

I got mine with 15k on the odo and have put another 1k miles on it this year with just an oil change. It runs great and i don't expect any problems for at least a few more years with minimal maintenance.

I wouldn't consider a bike as getting old until it gets over 30k or so miles on it. And as has been stated, they can go much, much longer than that. A lot of it depends on how well you take care of them.

 

Or how much you are willing to put in them.