Have always done my own maintenance on my XR4. For example: winterization, replaced things like reeds, switch boxes, trigger and stator, rebuild fuel pump and carbs, and have done regular LU water pump replaces.

Have never done any internal motor work (yet) though.

I see this 1999 Mercury EFI for sale. Sounds like it would be a good engine to pick up. I can put my XR4 on another boat I have, so no waste there.

The only info I have on this 1999 EFI is that there is a “cylinder skirt” problem stopping it “from turning”...

First of all I think the skirt is the bottom on the piston below the rings, not on the cylinder, correct?
Also, here is a start of my questions for the owner:

1) How would they know that was the problem without opening up the engine?

2) What was the case of the failure?

Aside from this, if it is just a piston failure, is there a good chance the cylinder is not affected and replacing the piston will take care of it? Any other questions I should ask?

Any input is welcome.