Not sure on the 2000, but think is the same sprockets as the 05s, 41 rear, 17 front. If this is the case on yours, going to a 46 on the rear, you would not be able to do any speeds above may 60-70, but could about change the rotation of the earth. Most are using smaller rear sprockets, 39-41 tooth, to lower thier crusing RPMs. Many also use an 18 tooth front, or some combonation of the above. Definetly advise changing both sprockets and chain at the same time. On the front, once you get the cover off, one bolt on rear of cover, just under the ignition.The nut should have a washer behind it that has at least 2 sides flated against the nut. Tap these away from the nut, and loosen the nut. This may be easier said than done. If you have an impact, use it! Comes off counterclockwise. May help to have helper hold front break to keep motor from rotating, and motor in gear. A broken tooth on the sprocket isnt good. Sounds like chain was skipping. Adjust chain to have 3/4 to 1 1/4 slack on bottom in the middle of distance between sprockets.