Ok, here's what to do. First, take your hi-speed needle out and thouroughly examine it for damage then clean it. I just spent 3 weeks trying to diagnose my engine running perpetually 330F before my LHS discovered my hi-speed needle had come off it's o-ring and was in fact not moving in or out when turned, leaving it with way too much air, but enough fuel to appear rich. Yours might be stuck really rich. After you've fixed that, reset your engine to slighty richer than the factory settings and start leaning it out 1/8 of a turn at a time while simultainiously checking your temperature until the temp gets up to around 220F - 230F after some runs, then go down to 1/16 or 1/32 of a turn at a time and perfect your tune while keeping your temperature under 280F. Also, if the water actually steams off you are running within the 230F - 240F range. If it just sits there forever you're below 220F, and if it fizzles off in under 1 & 1/2 seconds you're too hot. Judging by the pictures, your problem must be near the exhaust system since what you're seeing is caster oil that's already been through combustion. If it was a compression problem there would be fuel there too.

Hope that helps!