Home handyman....You need to clean the burner (usually will have some rust on it and can be brushed with a small wire brush and then blown out with air) and then wipe the gas orrifice at the other end of the burner tube with some alcohol. After you've done this, you'll find an adjustable collar on that burner tube that regulates the amount of air to be mixed with the gas. The collar has a set screw you can loosen and adjust. If the burner is not burning a combination of orange and blue with a steady flame, adjust the collar one way or the other. There should be no yellow in the flame.
The burner tube itself will often get a small spider in them and they build a web across the interior of the tube blocking flow. If you have issues with spiders, buy a dog flea collar at the store and cut it into two or three sections. Screw or wedge the sections into the back of the refer. This will keep spiders away for quite awhile.
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab