I was trying on some wheelies (2nd gear only), just pop up wheelies. From that day my bike doesn't sound good, every time when i change to 2nd gear i hear a weird crack sound, at times even the throttle misses not fully just a slight miss (only in 2nd gear) other gears run smooth.

Thanks.

all that happened after this -

 

Doesnt sound catastrophic. Forget the wheelies and go find some twisties.