RE: Screw too tight
before drilling it out, which runs a high risk of ruining your crankshaft, first go and get a [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXATDA&P=7]piston lock[/link] and try again. if that doesn't work use a dremel or an air saw and make a slit in the head and turn it into a flat head screw and then try unscrewing it with a flat head driver. if that doesnt work then some skillwork with a drill will be needed.