Hi I hope this is the place to ask about my Smev hob small burner its one of 3 burners 2 larger burners that are working OK the smaller one is getting gas but it does not get full flame could the jet be blocked do you have to take the plate off the top of the burner ( held on by 2 screws) they look a bit rusty anyone had the same problem ( using propane) thanks for any help.Robert.