I was on yamahas website a minute ago and was reading where they improved engine performance and it got me thinking. They went from the 400 to the 426 and then to the 450. And they keep improving and revising the 450. But eventually they will run out of things to enhance or revise engine wise. And as components get lighter and riders get faster I wonder if they will increase the displacement in the future. Just a thought lol. What are yalls opinions?