Why do my gas hob rings not burning equally around the cirference?

remove the top of one burner ,u will see a small jet . if u remove it ,u will probally find its blocked with grease . blow it clear with an air line, dont try cleaning it any other way and return it to its burner .if thats it sorted ,do the rest . ps these are arranged in a certain order don,t get them mixed up.by the way are u a corgi gas fitter if not u should,nt be working on gas applinces ,so be carefull