Ok, I figured I'd reach out to the forum community for some help.
For starters, I'm using a Master Forge 2-door propane smoker, Lowe's cheapo model. I noticed on my last smoke that I was having to throttle the gas using the manufacturers burner control. But the knob on the front and the actual valve itself has a lot of play in it, such that I could spin the knob a good 1/4" to 1/2" either direction before it actually "grabbed" the gas valve to make the change. This made it a bit touchy to dial in the right burner setting. I actually found it more efficient to set the burner, and then adjust the side vents to let more/less cold air in. This is fine for now, but I fear in the winter that's going to be an issue.
Anyway, I've read numerous posts on here and other places about the wonders of a needle valve. So I grabbed one off Amazon. I think it was King Kooker by branding, but from what I can tell the thing is nearly identical to the Bayou one so many people talk about, right down to the stamping marks on the sides and it being 1/4" threads - only a minor issue (or so I think) to get it mated into the 3/8" propane line for the burner.
After a trip to the local big box hardware store, I had enough brass fittings (including flared type male for gas) to accommodate the valve. I decided to install it where the flex hose (after the regulator) mates to the hard line on the smoker burner. After some wrenching and some soapy leak checking, I tried to light the burner...Nothing. I made sure the tank valve was open, I made sure the needle valve was open, nothing. I swapped from a half-full propane tank to a full tank, nothing.
I took the valve/fitting assembly off, hooked up the full tank with the propane line as the manufacturer intended, and the thing lit right off. Tried the half-tank, and again the thing lit right off.
I checked the valve assembly - I can blow air through that very easily, so I know the valve isn't plugged.
Any thoughts on what's going on? I've seen enough forum posts using the 1/4" needle valve to assume it should work. Did I miss something in the fittings I used that's tricking the regulator into thinking there's a leak and its shutting off gas flow? Or somehow putting back-pressure on the regulator and it's knocking the flow off for that?
With the needle valve installed, I don't hear any gas flow through the burner when I try to light it. Without the valve, there is a clear audible flow of gas to the burner before I push the igniter.
Would love some help on this. My smoker isn't dead in the water by any means, but I was planning to use the needle valve for a little better fine tuning.