I have a 2001 400ex. I drag race this bike and would like to get more power out of it. My local mechanic tells me that if done right that a 416 national kit will be more reliable than the 440 kits. He is also recommending that I contact Rocky Ridge racing to get all of my custom work. Does anyone have any input or info to help me out here?

 

Both the 440 and the 416 are reliable. The 416 could make a good drag racer over the 440, because the smaller bore will rev a little faster. I had my 440 stroker done through Powroll, and have a Web cam.

 

Thanks for your input. I am leaning more towards the 416 kit.