What i do before i start the engine is take the exhaust tubing wich goes to the tank en blow on it to let the fuel fill the tube wich goes to the carb.
Open the carb by hand and blow some more to let fuel in the carb.
Then start the engine on the startbox. If it doesn`t start right up something is wrong and extended time starting the engine on the startbox can damage your engine rod. I run 10th scale national racing by the way. The engine`s always fire right up. Almost imediatly. Some racers don`t like the taste of nitrofuel (toxic) so they close the exhaust with their finger and let the engine do some turns on the starterbox wich gives pressure on the fuelline also. I feel that it still does a few turns with no oil though.