Got a decent deal on a tagged 04 WR450. Rode one last year and loved it. Finally found a tagged one and jumped on it. Brought it home rode it around the neighborhood...then parked it and uncorked the exhaust and did the gray wire mod. Going to do airbox mod, throttle stop mod eventually along iwht air cut valve. I did notice when being easy on the throttle low rpm's and hitting it in second it does bog down. I am guessing that is the ACV? I also have to replace the chain and sprockets. I am looking at either 14/52 or 13/51. Not sure so tips would be nice. IF I stay with 14/52 the stock chain length will work correct? Thanks in advance for any advice.