The most common cause of that malady is a dirty jet. Remove it from the jet holder and blow the butane backwards through it then reassemble.

 

Is this the jet?

 

I seem to recall that covering the air hole at the burner will help with lighting - or did I get that wrong? (Does a Ruby have an air hole or collar?)

 

My gas burner loco's, particularly in cold weather, sometimes need an air hole blocked when lighting, usually with my finger, as a sort of 'choke' and the flame then pops back. I take my finger off after a few seconds and wait until the burner warms up before adjusting the flame as it's always unstable for a minute or so. But I would definitely check for a partially blocked jet and also maybe adjust the air collar ring , if it has one, for best flame. In warm weather they usually light up without the finger on one of the air holes.
Other factors could be , gas jet aligned properly centred in the burner or jet holder moved too far back?
Hope you get it sorted
Russell

 

I take a few strands of nicrome wire ( salvaged from a junkpile toaster ) and insert them over the burner tube. This makes the burner a hybrid radiant burner. I find it helps with lighting and whistling problems. Also can be run at a lower gas setting. Yes, clean the jet and make an air control collar as well.

 

Yes the jet is in the holder that pokes into the burner so undo the gland nut and it should be easy to remove, then unscrew the jet out of the holder and inspect for any debris like remnants of sealant or tape and reverse blow from your gas bottle filler to clear it. Hang on tight to the jet or it will fly off, you can then visually inspect by holding up bright light to compare to what light shone through before. Also in cold weather block the top air hole off with your finger ( like a choke) and you may find it lights easier.
Russell

 

the gland nut

(That's the big nut on the pipe from the gas tank.)

 

Since butane burns rather cleanly and if there are no alignment problems I would try to blow the gas supply line in reverse.
There could be a small obstruction such as metal shavings or any speck of dirt.

 

Hi Keith,
I see that you miss the ring/collar over your air mixture holes. The collar is used to get the correct air/gas mixture. So normally set to block the holes halfway, makes a very need smal flame inside the tube. My Ruby runs easy, without blowing of at 40 psi and with some load. Perfect.
So it take some time, good little flame and maximum endurance. However now it runs out of water before the gas is finished, little riskie. After 5 min some squeeses with goodall valve and bottle may give you a good running time.
Good luck 😉
Rgds
Kees

 

Here a picture of my settings

Accucraft Ruby

In Dutch, but you have the pictures
Kees