250-500cc Wr300 wont start. Sitting for a week after run out of fuel

Hi everyone,
My 2009 wr300 wont start. A couple of times it kicked but died. About 10 days ago it ran out of fuel. I switched to the reserve tank and came home (only just made it). I refuelled the bike but did not start it. Tried starting today with no luck. I removed the spark plug and squirted in aerostart. Didnt seem to help. In the end i noticed black (what looked like oil) coming out of the spark plug hole. I disconnectef the hose that runs from fuel tank to carby. It is getting fuel. Im worried about the black stuff coming out the spark plug hole. Any ideas?

your pilot jet could be clogged or there is goo build up in float bowl. carb floats could be off too - does it leak gas when tipped more than 45* either direction? If not, float could be too high.

You probably sucked some dirt or other crud from the bottom of your tank and clogged the pilot jet. The orifice is very small in the pilt and clogs easily, especially when running on deserve and emptying the tank.