Hi Larry,
Here are some ideas. I'm assuming this just started, so my first thought would be a problem with gas pressure. Make sure you have propane. Close propane tank valves and sloooooowly re-open. If still a problem, try running off one tank and then off the other. Try swapping tank positions.
BURNER LIGHTS, BUT FLAME IS TOO SMALL
Improper gas pressure------------------------------------------Check for gas leaks, have regulator checked by qualified LP gas technician
Improper air/gas mixture --------------------------------------Adjust air shutter if applicable
Problem burner valve --------------------------------------------Replace burner valve
Blocked orifice ------------------------------------------------------Clean with toothpick
OR
YELLOW FLAME TIPS
Improper gas-air mixture --------------------------------------Adjust air shutter if applicable
Low gas pressure--------------------------------------------------Check gas supply
Check for leaks and have the regulator checked
Set pressure to 11” water column
RA Ranges and Cooktops
Improper orifice to burner alignment --------------------Realign burner head and orifice tube assembly
Replace orifice