My engine started knocking the other day. The knock would speed up and slow down as I used the accelerator. We looked at it this afternoon took the top cover off and ruled out the rocker arms.
I found this YouTube vid with a Nox doing the same thing as mine. When I read thru the comments the OP had taken it to a mechanic and said it was the oil pump. What do ya'll think??
https://www.youtube.com/watch?v=CC--GnghHz8