Firstly - A warm
to the forum!
You don't appear to be getting a whole heap of moral support here do you?
Whilst I can fully understand why you're pi55ed off, I can also understand where the dealer/Yamaha UK are coming from too. It is pretty disheartening after you've got yourself all excited about a owning new bike only to find it develops a major fault and needs replacing. However, I'm pretty sure that whether it be a car or bike, Yamaha or otherwise, all dealers/manufacturers would probably do/offer the same solution? Defective product = replace it like for like.
As has been mentioned, you got 4 weeks use out of a new bike and stuck a few miles on it, miles that you won't have put on the replacement. When you think about it, the typical rental cost for a bike like the XT is about �395 a week, so �200 for 4 weeks riding doesn't sound too bad?
Like I said, I can empathise with you. I had a similar issue with Subaru a few years back. My Legacy needed a new engine due to a crank oil feed issue; the car had 22K miles on it at the time. They gave me a loan car (lower spec) and it was a petrol auto (which cost me as mine was a manual diesel). I was told my car needed to be at the dealers for two months! I was a little miffed at first (like you) and thought better of Subaru (I'd owned two faultless Imprezas before). The engine had to be shipped from Japan and realistically there was nothing I (or they) could do about it. However, to cut a long story short, it cost me money like your XT has, but I saw the bright side, I now had an 18 month old car with a 0 mile engine in it - I'd saved myself 22K miles of mechanical wear and tear, which suits me as I tend to buy new keep for the long haul. I hadn't, on the grand scale of things, come out of it too badly... It was a fair deal.
I'd say it sounds like you've got a reasonably fair deal too. Might not be what you wanted, but it is fair and as good as can be hoped for.
Hope you have better luck with your second new Tenere!