The documentation that came with it said to light it at 15 psi. I lit it at 10 and 15. It blasts out real hot and hard. Im actually afraid it might be too much. If the flame licked out of the forge and up to the jets there may be an issue. I think you're right about the small valves on the top. Again though the guide says he opens them and 1/8 a turn to light, then opens them up more. Maybe thats the end of adjusting them though. Just light it then open them fully and use the PSI valve to regulate the flame.
Thanks