Removing saltwater seized piston on Mariner 5hp

[eddie the boat guy]

Is there any way to remove a very seized piston by sacrificing the piston to save the cylinder, I have tried penetrating oil,brake fluid heat and the piston won't move a bit

 

[racerone]

If motor was submerged and then left sitting , then crank and bearings will be scrap.----Worth is scrap / parts value.

 

[eddie the boat guy]

If motor was submerged and then left sitting , then crank and bearings will be scrap.----Worth is scrap / parts value.

I know the crank is scrap I have a new crank and piston just need the cylinder

 

[Chris1956]

Stick a brass drift thru the spark plug hole and give it a rap with a 4 pound hammer.

 

[racerone]

Putting it in a freezer might shrink the piston a bit to help remove it.----But the cylinder will be corroded.----Perhaps distorted as well.-----It may run after all the work.----I think there are better projects available !

 

[Scott Danforth]

heat the cylinder, then use a can of freeze-it on the piston.

another idea, use a hole-saw that is the diameter of the inside ring grooves. you have to be dead-centered on the piston. you saw thru the piston, and the piston comes out in bits, then you can peal the rusted rings from the bores.

 

[flyingscott]

If the head comes off of that motor you can try this. Mix ATF and acetone together in a 50/50 mix and fill the cylinder. Let it sit a week pull the head off and find a Hydraulic press and take your chances.