Screw it down all the way unless your having trouble turning it over. You can loosen it but if you can turn it over you are just making more trouble for yourself. Ensure everything is completely charged up, If you have not got a zip tie round the airfilter remove it and add a few drops of fuel down the carb, then replace the filter and pull on the starter (with the igniter on of course). If the air filter is zip tied on, then cover the exhaust with your finger and pull 3-4 times to prime the carb (you should see the fuel enter the carb through the tubing). Now put on the igniter and start pulling. If it starts but dies on throttle you will need to lean the HSN a little (just 1/8th turn for a start) and try again.
I find a few drops of fuel in the carb works best though.