Hi ydna,
I don't know if the chain has a service life,
I've never seen a post about one going pop and my red ST has 135K with the same chain
When I got my first ST150, this was something I was concerned about as I remember the Granada 2.8 or 2.9 chains self detructing around 80,000 miles as the damage was so catastroupic, we never got to the bottom of wether it was just a case of the chain breaking, or it jumping due to knackered tensioner.
I am changing the cams on this engine, so logically now would be a logical time for new chain/guides/tensioner, but as with the water pump I could end up buying parts of ÂŁ200+ for no real reason.
Furher info required
Al