...do you get from the front edge of the lid (under the handle) on your YS640?
Very little to none. All my smoke seems to come out of chimney, once I am cooking. In start up some comes out from under lid. Yoder Herb will be able to give more specific answer.
Check the corners of the front of the lid to see if they are pushed in or if the front edge is straight. If they appear to be pushed in a little, use a rag over the corner to protect the paint, and use a crescent wrench to gently straighten the corners.
For me, it depends on the cooking temp. When I smoke, 225, I don't get much smoke leakage at all. When I do direct grilling, temps close to 500 degrees, I get a lot of smoke leakage because at the higher temps, the metal expands thus the leakage. Hope this helps.
I had quite a bit on mine. I purchased some heat seal/tape and it has solved the issue completely. I put it on the sides and the bottom and now the door fits like a glove. I bought it online, but have since seen it wherever there's a dealer for Green Egg's. You can use their seal tape just as easily. You'll find it much cheaper on Amazon though... Anyway, I've had it on for over a year and it has totally held up. Also, I put it on the door, not the unit itself.
my brand new Yoder 640 leaks around the entire door and I was told thats the way it was designed...
The door may not be adjusted properly. Someone else had a similar issue and Herb gave instructions on how to adjust.
After mine has got to temp, it quits. It's just during the initial start up that it leaks a little. But every smoker I have does this. I think where it's producing more smoke, it leaks a little and a combination of the metal heating and sealing as well.