Ken, you need to put a check valve on the 4mm line that goes direct to the turbine (of course you will need to come down from 4mm to 3mm for jetcat). The check valve is paramount cause gases will come back up the line if you don't have it and will melt a festo fitting inside the engine (ask me how I know).

Then hook up the regulated propane, put a click of propane as the start sequence starts.

I don't even look at the GSU anymore, but I think I did when I first started.

You can hear it light off, and start up, when you think you are at sufficient speed and temp (I go by how it sounds, and I'm way accurate), shut it off, and pull the 4mm line off the check.

If you have any probs or questions, pm me for phone number, I'll walk you through it. It's easy, and IMO the best way to do this. I've turned over at least a dozen guys to this.