. This is a pretty sophisticated launcher, specially' being your first. I'd be interested to know the results of the max. pressure gauge. The purge valve is also a good idea. Is that venting the chamer well? Have you been shooting it? How's the performance?
. I used a ruler thing to measure your photo. It looks like the combustion chamber, which includes the 4" pipe, rubber hose and PVC "U", might measure , maybe, about 260ci or 4260cc. Taking more guesses, I'll assume your altitude at sea level and the 'operating pressure' of your tank at full open around ,maybe 90PSI. Your meter looks like a 3/8"x8" pipe. It all this were true, you'd only be getting a propane mix of .033, lean but igniteable. To get a .04 mix you'd need more pressure (already maxed) or a larger meter, 3/8"x9.7" might get .040 at 90 PSI. Since you already have that fancy frickin' regulator, it might be good to set it at anything but the fluctuating wide open position. Insted try setting it at a level you can control and a level the tank is not likely to drop below....say 60 PSI. At 60 PSI, your existing meter would shurely be too small. A switch to a 3/8"x 14.5" or a 1/2"x8" meter pipe would put you at .040 mix at 60 PSI. All of this is a guess. Like I asked, "How's it shoot?"
. These calculations are easy to figure out using the new propane calculator available, maybe tommorow, at http://burntlatke.host.sk/lp.html
The new calculator is called Fuel Tool 1.5. The old propane calculator is available now at the above address.
. Lots of good ideas on your launcher. Let us know how they perform.
BTW, have the doctor check out that flapper on your R. rod, better safe than sorry. : )