Johnson 35hp knocking sound

[raksike]

My old Johnson 35hp is doing some knocking noise when it runs, should i worry about that or is normal?

Video, when the motor is running:

https://www.youtube.com/watch?v=FXArnizOvsY

 

[raksike]

I have to check the model number, but it was a 1978 year model.

Here is another video when the motor is running without the cowl:
https://www.youtube.com/watch?v=jn2XTafXP9o

 

[Boobie]

What's the gear case oil look like ?? Any water or metal chunks ??