This is Curtsey of the:
Lantern burns yellow.
What it is Not Working Properly:
A lantern requires fuel and air to operate. A yellow-ish burning lantern generally indicates a lack of post-vapor air.
Fuel vapor that shoots out the top of the generator is mixed with a free supply of air. The mixing is done at the very top of the lantern, a part called the mixing chamber. Air is supplied to the mixing chamber from one or two air intake tubes. On double mantle lanterns or newer single mantles the air intake tube is the large tube running in the near-center of the lantern, from the fount to the top. The generator goes into this air intake tube. On an older single mantle lantern or a military lantern the air intake tubes are camoflouged as "stuts." They are the two side posts that hold up the top of the lantern. One or both of them are hollow and they are the air source.
Your problem should already be fairly obvious. You have an obstruction somewhere in the path of the air. Your friendly neighborhood spider population will more than likely be the source of this blockage. They love dark spaces and places and what better than a small dark tube? A year or two of spider homes and all of a sudden the air can no longer flow into the mixing chamber. And then the lantern will not get past the yellow stage. Bummer!
To fix this you need to clean out the entire burner assembly. To clean it you have to remove it from the lantern. If you need help pulling apart the lantern to a point where you can clean the burner please refer to our Rebuild Instructions. You will need to clean the air intake tube(s), the mixing chamber and the burner tube(s). Best for this is a combination of rifle bore brushes and compresses air. Without the compressed air, blow out the tubes best you can with your lungs, after cleaning with the bore brush.
Your lantern left Wichita Kansas with a pre-set and well-engineered fuel/air mixture built into the lantern. DO NOT do anything to change the amount of air applied to the mixing chamber! If you find a metal cap on one of the frame struts, leave it alone! Altering the function of any part of the lantern is not only unnecessary but can also be dangerous. DON'T DO IT!