Water in exhaust manifolds

[Lou C]

I see some light scuffing on the cyl wall in the 1st pic, definitely a valve seal leak in one cyl, also the motor was rebuilt at some point because I see a piston stamped .030”.
Looks like some very light corrosion in one of the pix as well. Nothing too bad though….

 

[Scott Danforth]

Holy detonation pock marks batman.

Agree with Lou. Someone has been in the motor before

 

[chartersj]

I see some light scuffing on the cyl wall in the 1st pic, definitely a valve seal leak in one cyl, also the motor was rebuilt at some point because I see a piston stamped .030”.
Looks like some very light corrosion in one of the pix as well. Nothing too bad though….

Yeah I bought the boat with roughly 100 hours on a rebuild. I’ve since put another 100 on it. To me it didn’t look like water had been running though it too much if any. A week before I initially pulled the risers I did leave the boat in salt water for a week. Which I normally don’t do. I would think if salt had been laying around I would have seen more traces of rust

 

[chartersj]

Holy detonation pock marks batman.

Agree with Lou. Someone has been in the motor before

What would be the reasoning for detonation?