Okay so I have a 2007 Yamaha YFZ450 SE. The guy that I got it from put a 40 tooth sprocket on the back and a 13 tooth sprocket on the front. I don't ride dunes but I did plan on doing a little bit of hill climbing and maybe some racing. Is that sprocket setup okay for what I'm trying to do? And when I let off the throttle it almost feels like I'm hitting the brakes. Also feels like first and second gear ain't even there. Any help would be appreciated.