Can't seem to get up to temp

[ed thayer]

Just purchased the Pro Series LP smoker and we're using it for the first time.  When filled with pork butts, the smoker can barely get up to 175 degrees.  I observed the flames while set to the highest temp and I'm getting maybe 3/4 inch blue flames which just don't seem high enough to get the unit up to temp.  we plan to use the smoker at a festival and could really use any suggestions for getting the temp up past luke warm.

Ed