question about engine exhaust

[Five Spice]

When flushing out the salt water from the engine, black sooty substance is being spat out. Pretty sure its carbon?? But it seems somewhat viscous like oil. There seems to be more unburned gasoline than should be present. My 2-stroke seems to burn a heck of a lot of fuel about 30 gallons running 4200 rpm for about 45 minutes total.

Is any of this normal for a 2000 Yamaha 200 OX66?