broke bolt off in head

[Troutkiller2006]

i broke the top port side thermostat housing bolt in the head of my merc 225 2stroke, damnit! when pulling the motor off my chapparal so i could use it on the dually im getting that bolt looked like a good spot to secure the lift.when loosening it it turned maybe 1/8 of a turn before it snapped.

im seriously considering letting it slide and running the motor as is. its a 97 3.0 liter and that thing been on there a long time. i think if i keep an eye on it worse case it might leak a little but i dont think it woud put the motor in any danger if it does. and if it does leak i can deal with it then.what do you guys think?