What are the characteristics of a the 270 degree parallel twin in terms of engine sound, vibration etc. I have a 2015 nc700 that's going in for its first 600 mile service. I bought it brand new. I had a bit of a concern that the engine had a clackity clack, almost piston slap(ish) sound at idle. I took it in and they listened and said it was just the character of the 270 degree engine. They even pulled another one off the floor and started it up.