Mercury 1994 2.0L 150

[FMP]

Could always try a warm weak acid bath 5 pH to try dissolving the mineralization. Carbonic or citric acid, changing it occasionally to maintain the pH range.

[Glastron1987]

Last couple of previous posts not my choice of words, but does express my feelings accurately.

[bullet123]

I've had to this more than once. Salt motors suck!! I don't even bother trying to separate anymore until I take a 4 1/2 grinder with a good zipwheel and cut the four longer bolts through the upper exhaust plate. exhaust plates are easily replaced.

[Glastron1987]

So if there is a next time on this, I'll head for the cutting much sooner.

This weekend I'm hoping to get to this. What I'm thinking is that if I use a drill instead of the cutter, the plate should be quite reusable. Any drawback to that?

[bullet123]

What are you going to drill?

[Glastron1987]

The top plate like this:

https://www.youtube.com/watch?v=Bms03orDMgk

[bullet123]

I was just trying to save you time and aggravation. I can do it in 15 minutes. I never had much luck drilling stainless surrounded by aluminum with a round surface. Usually walks and wollers.

[Glastron1987]

Maybe I'll try one with the drill and see how it goes, but I am in the mood for something easy.

[Bruce2]

A machinist carbide centering drill bit would be great to use first and then a small drill bit for the pilot hole then increase your sizes as you go, maybe you would have more of a chance getting in the center of bolt.

[Glastron1987]

Drilling even with normal bits actually wasn't too bad. Took me about 2.5 hours for all 4. Started with smaller bits and worked up to my largest 1/2", cleaning the chips away and oiling regularly. If the suds are stainless, they didn't seem too difficult to get though.

However, there are two issues: 1) getting the hole centered on the stud was very difficult to judge with the irregular shape of the plates, and 2) judging when to stop drilling in order to save the plate was also quite difficult.

Maybe from the photos you can see that I missed center on probably all four studs, as there is still some stud left on each. Also, I probably drilled all the way through 3 out for 4 holes, so I assume the plate is no longer usable at this point.

So as most of you advised, I’ll be grinding next (which should have been first).

[bullet123]

Well, atleast you have it separated

[Glastron1987]

Actually the photos may not be great, but there was no separation or budging of any sort after drilling. So I finally did attempt to use the pneumatic 3" die grinder. That was even too weak to cut adequately. Thinking of “Tool Expectation #5” I finally resorted to my 7” industrial angle grinder with a cutoff. That did it… easily, in minutes!

[bullet123]

That’s the ticket!!

[Glastron1987]

Any tricks on getting the remaining stud stumps out of the block. Or should just some vice grips do it? Some came out by hand. I'm a little concerned about those tenacious ones.

[bullet123]

Usually aren't too bad, but...... Start with vice grips or good little pipe wrench. might have to put flat spots on them with a grinder to get better grip.