So yesterday I tore my 96 ZX600 down to the head: I was determined to get at the head gasket to see if it was foocked up. b/c the bike was having a few tell tale problems such as sweet smelling exhaust and oil leaking out of the exhaust pipes. What does a blown head gasket look like by the way, b/c this one doesn't look that bad: granted I've never seen a bad head gasket or a good one before, so I have no idea; but I kinda expected it to be obvious. All the black stuff is just the sealer I presume? Anyways, one thing I noticed was that the spark plugs from cylinders 1,2, and 3 all appeared to have oil on them; the cylinder heads seem to back this assumption since 1-3 are black and 4 is just brown. But what do I know, I've never done this shit before. here are pictures: Cylinder 1 is on the very left and then they go in order. So, what now? P.S. throughout this process of tearing the bike apart I have learned that the whole cooling system is rusted to shit.