Just purchased a used Honda. Decided to change the oil before riding. The oil nut had some type of liquid nail around it (or weld). I pulled it away and unscrewed the nut. I then realized the screw hole was busted. The entire threads broke into pieces and part of it actually pushed back into the crankcase. I dont' suppose there is a fix for this besides replacing the entire crankcase. The previous owner really screwed me. What can I do to fix this????