engine knock?

[99blasterzach]

i think both of my blaster have knocks in them because they sound like this
.

my old blaster

new one

whats this mean? new top end?
also i just took pics of the piston on the intake side and it had a couple screches but not many

 

[jbuckster07]

Sounded to me like it took a lot of time to come down from revs in the last video. Think I would leak test it. Whats the main jet?

 

[99blasterzach]

Sounded to me like it took a lot of time to come down from revs in the last video. Think I would leak test it. Whats the main jet?

im not sure but i know it was too lean at the end