I have heard dealers speculating engine changes because of the Euro emission standards. If I was going to guess. I think you will see the migration of the 821 motor into the Scrambler. Maybe for Euro models in the beginning while offering the air cooled motor in other markets. One of the benefits of a non euro manufacturing ability. Only time will tell.
there won't be changes cause of Euro 6 because for motorcycles it is determining when the type test was made.
Since the Scrambler was tested in 2015 there won't be a problem.
They will never bring a watercooled engine in the Scrambler for 2016.
Btw. I just had a look, Euro 6 and Euro 5 is just for cars, motorbikes have from the 1st January 2016 Euro 4.
I feel like for now. . And I reserve the right to change my mind later. . There is little use for much more power out of the scrambler. . With the ergos the way they are, vastly more power would be hell on the shoulder sockets.
As I mentioned earlier, they won't build a new engine just for the scrambler, instead they will take an existing one out of the shelf, like the one from the old 1100 evo monster. It's air cooled and has more power than the engine of the Scrambler 800 which is from the old monster 796.
Since there is only one smaller engine, the one from the 696, and that one is too close to the Scrambler 800 engine, there won't be a smaller Scrambler.
Furthermore if Ducati would devolp a new smaller engine, just for the scrambler, they would have to have a market to sell it on their mind. So where do you sell a small Scrambler? Certainly not in Europe or the US. In Europe you could drive a 400cc engine with a learners license, but there are kits for the 800cc Scrambler and the price of a 400cc Scrambler wouldn't be much lower, not many people would buy the small one instead.
That leaves the asian market. If I'm informed right you can drive a motorbike up to 250cc without/with a small drivers license in some asian countrys. That's why Kawasaki and Honda have 250cc bikes. A 400cc Scrambler would still be too big for that. So no market in Asia either ,having in mind, that the price difference can't be huge. Ducati would have to earn a lot of money to get the investment for the development of the new engine back in again. I can't see that for a 400cc.