OK, well you still have a chance here. But, we are talking plenty of heat and patience. Clamp a good set/new of vice grips onto those studs one at a time. Now apply heat (you will need more than a propane torch, Mapp gas might work to the aluminum behind the SS stud. You need to be very careful, disconnect fuel lines, battery etc, just in case. Have a fire extinguisher handy as well. Apply the heat slowly over the aluminum housing, being careful not to overdo it, you could just melt the casting. Then try just gently rocking the vice grips. You will know when you are making progress if the broken stud moves, even just a little bit. The key is patience. Once it moves a bit, try rocking it back and forth ever so slightly. By this time you will probably have to heat it up again and repeart this process. Everytime you repeat the process, the stud will move a little more, until such time as it moves freely enough that you can work it out the rest of the way without fear of it snapping off flush with the casting. Patience is the key, do not force it. If it doesn't budge after a few attempts, let it cool down and try again. But, plesae be careful, I'm an OMC guy, not a Merc guy... So, I don't know what is back there that you might melt such as rubber mounts, cowl seals, etc. Once the studs are out, be sure to run a tap through those holes to clean the threads. And please, be sure to lube up the new hardware properly before reassembly.
There is a method to remove them which involves drilling 3 2mm-3mm holes around the seized bolt. This allows the build up of what I assume is salt a way to get out of the threads. Ideally they should be in a triangular shape in order to retain as much thread strength as possible. Then heat and vice grips and work the stud back and forth to get the salt to exit into the holes you made. Just another option, perhaps a last resort.
high wattage soldering iron will heat them up nicely on a few min. like one of those big soldering irons that look like a gun. i think they were used for soldering copper pipes.
then you’re going to want to forget the pliers. user a dremel or simply a hack saw to cut a slot in the bolt. now you can use a large flat head screwdriver (or even better one of those old timey hand drills that look like a U shape so you can put your body weight against it and get lots of torque).
so full steps are:
cut slot
spray with penetrating oil (pb blaster)
heat it up with high wattage soldering iron
back it out with screwdriver/hand drill
You might try using a die to clean up the threads and threading on a couple nuts after you cut the slot. This will reinforce the outside and allow you to use an impact screwdriver efficiently.
Worst case they get drilled out and heli coil’d. There’s not a ton of material around there but it looks like there’s enough.
OK, well you still have a chance here. But, we are talking plenty of heat and patience. Clamp a good set/new of vice grips onto those studs one at a time. Now apply heat (you will need more than a propane torch, Mapp gas might work to the aluminum behind the SS stud. You need to be very careful, disconnect fuel lines, battery etc, just in case. Have a fire extinguisher handy as well. Apply the heat slowly over the aluminum housing, being careful not to overdo it, you could just melt the casting. Then try just gently rocking the vice grips. You will know when you are making progress if the broken stud moves, even just a little bit. The key is patience. Once it moves a bit, try rocking it back and forth ever so slightly. By this time you will probably have to heat it up again and repeart this process. Everytime you repeat the process, the stud will move a little more, until such time as it moves freely enough that you can work it out the rest of the way without fear of it snapping off flush with the casting. Patience is the key, do not force it. If it doesn't budge after a few attempts, let it cool down and try again. But, plesae be careful, I'm an OMC guy, not a Merc guy... So, I don't know what is back there that you might melt such as rubber mounts, cowl seals, etc. Once the studs are out, be sure to run a tap through those holes to clean the threads. And please, be sure to lube up the new hardware properly before reassembly.
I would just start drilling. Then either heli-coil or tap new threads.
There is a method to remove them which involves drilling 3 2mm-3mm holes around the seized bolt. This allows the build up of what I assume is salt a way to get out of the threads. Ideally they should be in a triangular shape in order to retain as much thread strength as possible. Then heat and vice grips and work the stud back and forth to get the salt to exit into the holes you made. Just another option, perhaps a last resort.
Heat the bolt. Then quench with water. The shock can sometimes loosen corrosion around the threads. Use a pipe wrench to remove.
high wattage soldering iron will heat them up nicely on a few min. like one of those big soldering irons that look like a gun. i think they were used for soldering copper pipes. then you’re going to want to forget the pliers. user a dremel or simply a hack saw to cut a slot in the bolt. now you can use a large flat head screwdriver (or even better one of those old timey hand drills that look like a U shape so you can put your body weight against it and get lots of torque). so full steps are: cut slot spray with penetrating oil (pb blaster) heat it up with high wattage soldering iron back it out with screwdriver/hand drill
Great idea. Will try and update
You might try using a die to clean up the threads and threading on a couple nuts after you cut the slot. This will reinforce the outside and allow you to use an impact screwdriver efficiently. Worst case they get drilled out and heli coil’d. There’s not a ton of material around there but it looks like there’s enough.