Mark,
I built a propane adapter using a BernzOMatic torch head ($12.97 at Lowes with a tank).
I unscrewed the torch tip and chased the threads with a 1/8" NPT tap, I then had to drill out the orfice in the tip of the tourch. I then bought 1/8" NPT Tee and screwed it onto the torch head, I had a bunch of gauges from freon refill adapters (Advance Auto) and used a 1/8" NPT barbed adapter to interface with the hose.

The cool thing is if you keep the pressure in the blue zone on the gauge the engine will light off with no extra flames with the new larger orifice.

Rich