I bought a chain and sprocket kit for my trx450r, and when I removed the front sprocket (I bought the bike used) I noticed the front sprocket is 13t and the kit I had was 14. SO i removed everything orderd a 13t front sprocket. During that waiting period I left the country and now I am back with my new 13t front arrived... however the shop manual that I have doesn't have any details on replacing and one side has a protrusion while the other side is flat. I don't remember which side on the old sprocket goes in. Can anyone chime in give me advice on this matter. Thanks in advance.

 

The side with the protrusion faces out.