85 40HP Johnson Banging and Rattling with Video

[Shawnwswan]

Hi, Looking for some help. I have an 85 40hp Johnson that just started making a loud banging noise from within the engine. I haven't had any issues with it up until this point. It sounds like something is loose and the noise gets faster when the engine is rev'd. It did not seem to affect the performance of the boat, I could still go fast.
Video link below to the engine idling and me reving it. Any ideas?
https://youtu.be/soJM4Y2MGME

Thanks in advance.
Shawn

 

[Bosunsmate]

I wouldnt move it again until you know whats up, treat it like a spinal patient.
Do a compression test and check the wrist pin /big end bearings for wobble by moving piston to TDC and checking they a tight by pushing on it with a screwdriver through sparkplug hole

 

[Faztbullet]

Its needs rebuild....

 

[Shawnwswan]

Thanks for the info guys. I have to run it at least one more time to get it back to the cottage where the other boat is. If it's going to require a rebuild I'll probably just sell it.