2011 Jonway/Roketa 250cc update

[Ebuddy]

Could you have had too much oil in it? Perhaps pressure build up, only temporarily forced oil into the cooling system (which might also have messed up the sensor). When you changed everything out you had the correct quantity of all fluids. Carb might have been coincidence. The only other thing that comes to mind is that you said it was spitting black out of a radiator hose, but the cooling system is closed. Could it have been another hose instead? In that case, maybe you were getting oil blow back into the air filter assembly, which was in turn getting back to the carb and gunking it up. Just some thoughts...