Those crush gaskets get dirty and look like the rest of your exhaust port, I bet they're there.
As for your smoking, here's my guess:
You went down on the pipes and loosened them, coolant poured all over the motor and ran down inside the pipes where it settled until they got hot enough to boil it. If the bike was actually kicking water out the pipes, if your motor was eating that much coolant, I don't think it would run.
Hope that's the case anyway. If you indeed do not have crush gaskets in there then that would back up my 'coolant getting into the pipes' theory.