The transmission doesn't red line on speedometer til 80 mph, but when the engine reaches its 7500 rpm red line you are only going 65 mph. Many others comment the same performance. If there was an easy way to get 5 to 10 more mph I would like to try it, but I do hate to modify from stock when it comes to the engine and transmission since I figured they knew what they were doing when they designed it. I may just wait for the xciting 400 or get a 500. I do like my 250 very much, I just wish it would go 70. This limitation keeps me off any stretch of interstate, and a new Interstate is opening here in South Western Indiana this fall.