Rick, Over the years in So. Cal. it can get hot out here. I have experienced with lanterns burning 24/7 and when there in the sun with them burning during the day with the sun hitting them already being lit and the metal and kerosene expanding the flame will grow and so all I can do is check them during the day. The wick will build up carbon. All you can do is clean the wick by eliminating the chard part with a metal brush. After burning a long time maintance is required. I use a pair of wire dike cutters to eliminate the used part of the wick about 1/8" below the burner to start a fresh part of the wick. It saves me the time from going thru the hassle of doing a major clean up. I would just replace the wick or just trim the top of the wick. I have bought the wick from Woody by the roll so if I had to replace it it's no problem. But different climate and wheather may play games with the cotton wicks. Hope you have better luck with your lanterns. Keep tring to clean your wicks and good luck. Great subject you brought up. Keep on burning. Steve.