The triangle of fire
Understanding the triangle of fire is almost always the answer to all the problems one can have with an oil lamp.The triangle of fire consists of three elements, when in harmony, create nice, steady flames. The elements are Oxygen, Fuel and Heat. 
-Fuel is your lamp oil. The wick and lamp oil can cause the problems. 
-Oxygen goes in the burner trough and alongside the flames. The burner and the chimney can cause the problems.
-Heat is created by burning the oil. The oil causes the problem.
In this troubleshooting series we are going to explain different problems that occur from time to time when using oil lamps.  My burner mechanism is stuck
The burner mechanism sometimes gets stuck. This is mostly caused by using a low quality paraffin based lamp oil in combination with not burning the lamp for a while. The solvent in the oil evaporates leaving paraffin in the wick and mechanism. The paraffin hardens and the wick gets stuck in the mechanism  eventually. To make it work again, take out the burner mechanism and boil it in just clean water for two to four hours. This will remove the paraffin from the mechanism and will make it work smooth again. Boiling your burner mechanism is best done outside because of nasty (paraffin) odours.