Re: Mercury KF7 rusted tight powerhead

[20mercman]

If the rings are above the ports so the cylinder is sealed, then I would use the ATF and acetone mixture and fill it up and let it soak. I have a spark plug end that I welded a zerk fitting to and I add a pump of grease to it. This will force the ATF/Acetone mix down to the rings. I let it sit for a day, then give it a few more pumps. If the piston is down below the ports, the old tractor folks use wax to seal up the ports first and then fill it with penetrant.

Steve