In the inexpensive Worthington brand torch there is a check ball that becomes stuck in the part that inserts into the propane tank. Using a #60ish drill I was able to push on the check ball firmly, hearing and feeling a tiny "snap" when the ball released. I then pushed the ball numerous times compressing the spring below the ball till the ball stopped sticking and moved freely. Did this on two torches where the flame was almost nonexistent. They run strong except when the propane tank is at zero degrees or below.