Re: 1988 Force 125HP head bolt torque?
You "could" use another bolt, but you SHOULD go to Mercury and get the right one.
You are gonna need a new head gasket anyway, as that one is probably crushed beyond use.
Subject of broken bolts has been discussed many times.
You can try the search feature looking for "broken bolt" or "bolt removal".
Removal depends on condition.
Drill it, then easy-out bolt remover.
Or weld another bolt onto it, then turn it out.
Or drill it out and re-tap the block.