Tanaka m700 Long mag not working right

Yea, my tanaka m700 long magazine isn't working right, and it's brand new. The gas doesn't wana seem to go in where the hole is, and will spray everywhere..i am holding it straight up and down, nd the can of propane as well. Then when shootin, the 1st shot usually wont fire, then next will be weak, and by the 3rd or 4th one, it sounds okay, and sometimes, it just is weak the whole way. Also, I can't really tell when my mag is full, due to problem number one. HELP ME PLEASE!!