How Many Miles

[Fazerider]

If you mean "When does it cease to have significant trade-in value?", then most dealers will have lost interest at around 35,000 miles and will only take it to sell on to a breaker.
If you mean "How long does a FZS600 last?", then there's no real limit while there's an ample supply of perfectly good bikes being dismantled. I'm happy to spend as much as the bike is worth on spares each year because it works out cheaper than the depreciation on a new bike.