I wouldn't run any gas appliance if there are flames coming from anywhere but the burner...that's a sure-fire recipe for disaster.
I lost most of the gas components in a large brinkmann gas grill, not due to a gas leak, but due to a backdraft/down draft from a wind gust...flames coming out the bottom of the grill (from the "H" burners) caught the propane hose on fire and burned it in two, and I'm told there were about 7-8 ft flames streaming across underneath and out the opposite side of the grill when they got the tank valve closed. Luckily no one was injured, and no other property was damaged...it could have been a very bad day in the neighborhood.
Inspect the gas components for any signs of physical damage (cracks, bends or breaks).
Make sure all fittings are properly sealed and tightened...use 1-1/4 wrap of teflon thread tape or a dab or pipe thread sealant...do not not overtighten, as that can damage the threads and cause leakage as well.
Be sure everthing is alligned correctly where the gas venturi tube enters the burner plenum, and that they mate-up/seat correctly. Also, be sure any screens on the venturi/plenum tubes are clean and free of spider webs, grease and dirt.
Before lighting any gas rig, you should check for gas leaks on the entire length of the hose, the tank connection, gas regulator, burner control valve(s) and all line/hose fittings. A good way to check is by spraying with a solution of water and liquid dish soap from a household pump spray bottle. Small leaks will slowly develop a small bubble, while higher volumes will create larger, more rapidly developing bubbles a froth or foam, and may be audible as well. Make an attemp to correct any leaks you find, then chaeck again for leaks before lighting.
Follow the manufacturers instructions for use, care and precautions. If you do not have the original user's/owner's manual, most manufacturers have free on-line PDF downloads for most recent and currently available models.
Lastly, don't operate them in an area which is prone to gusty winds...wind is your worst enemy with most any outdoor cooker, and can cause flame-out conditions (or worse) with gas smokers and grills.