Yamaha 2006 f90 four stroke noise.

[Norton75]

Hello: I'm new to the forum and right away I need help. I added a YouTube link showing a motor making the same noise. Does anyone know what it is!!
https://youtu.be/2IC_0yAQK9Q

 

[dark_star]

Sounds like a piston.

 

[Norton75]

Thanks for the input dark_star! I thought it was rod/piston but I got word today that my lower unit is the cause!$$$$$$