Hearing tapping noise.

I just got done riding all day today and yesterday. While riding I happened to hear a tapping or clicking noise where the filter and engine is. So I rechecked it and held the break and reved it a little and heard it again. Put it in neutral and still heard it. Any idea what this is from?
Thanks!

96 Honda TRX300 fourtrax



Another question is I did a little tuning to my clutch and ended up screwing the nut and tightened the screw and lost order in where it was. Could this make that noise?
I also found that it doesn't have the power or take off like it did before I messed with it?..