I added a 1/4 inch tee into the fuel line the went from the tee to a 1/4 inch needle valve to adjust the drip/min. ratio. I used high pressure fuel injection line as this system has around 75 psi from the pump. Carbureted vehicles have only around 4 - 8 psi from the pump. I'm at approximately 28 - 30 drips per minute right now to maintain the fuel level in the vaporizer.