I'd be very surprised if these bikes would have a speed limiter. On very long straight or slightly downward sloping highway stretches I've seen figures slightly above 180 kmph (i believe 183 or 186 was the tallest number) on both a stock X and an F also - pretty much reaching the rev limiter on stock gearing. Therefore I rather believe the bike in stock form limited by the rev limit in 6th, otherwise horsepower limited on longer gearing.I have tried many different gearing setups on the track and I have the PCV with the rev extend and there is definitely a speed limiter built in at 110 mph.
Keep in mind, that the figures are speedo indicated, I live @ almost sea level and ride EU spec bikes which might be slightly different (e.g. the velocity stack is different for the stock eu bike from the US and AU version).