Hi I bought a weber 640 it is quite a grill but I have a few issues with it . Nuber one if it sit out in the rain it seems to start to rust on the shelves with a little elbow grease and some soap and water it cleans up so Iput it under cover after useing and it has not done this since. The other problem is with lighting the burners some times they dont light when you turn the knob it takes several tries to get some of the burners lit usually 2 of the 6 will do this and it is not the same ones all the time any ideas thanks .TIM