What's the best big bore kit for a 2014 yfz450r? Also what cc's is the best kit. I know there are plenty of 480 kits but wouldn't the 525 kits be better since they give you more cc's? I mean I could be wrong so that's why im here. I want to get a lot more power out of my quad. I'm having trouble beating my cousins kawi kfx700 that's been modded out. We are equal in power right now. Neither of us can beat each other.