Hi Stovies, My Svea 123R (Taiwan) has an unevenly distributed flame coming out of the spreader. Two vents on one side have high and yellow tipped flame. The other two have weak but blue flame. I reinstalled the spreader after a 180 degree turn. The flame pattern remained the same - those previously high sides still got high flame. Could it be something wrong with the jet orifice?
I took out the jet and could see the stem inside was very clean. The cleaning needle block was even shiny. No carbon buildup was found in or around the jet orifice. I tried to turn the burner bell with a plier while the stove was on, and could see the flame pattern followed my turn. So I suspect the problem may still be with the bell/spreader being angled/warped in some way. I just cannot see it with my naked eyes though.
I may have found the cause. I compared my stove with the original Svea 123 pictures. The spreader on the original one sits much higher, with its top edge nearly flush with the rim of the burner bell. My spreader sat much deeper into the bowl. After raising the plate, the flame gets much bluer now than before. It just need some fine tweaks to get the pattern even. The stove was purchased more than 10-15 years ago. Maybe it was one of the defects from the early production in Taiwan?
My 123r of the same era displayed a unbalanced flame pattern. I gently lifted the flame plate and now it burns far better with a blue flame throughout firing range. I think the increased air flow improves the fuel and air ratio.
I've had one cast iron flame plate on a Primius 96 that threw the flame off as rotating the bell made the flame follow it, tried another plate and resolved it. Duane
The vaporized fuel exiting the nipple needs to be clear of obstacles. Check the top and hole of the jet. Check that the bell is not cockeyed. Even out the tabs of the flame plate. Make sure to anneal it before bending. Check for cracks, too.
Thanks everyone for chiming in! I have lifted up the burner plate slightly above the rim of the burner bell. Now I can finally hear the sputtering sound. Love it! I noticed the burner bell did not sit up right when fully screwed onto the stem. Maybe the threads were not properly machined. If I just unscrew the bell for a half turn, it would become levelled and give a better flame pattern.