Thanks, I fixed the top vent by loosening the screw and lubricating. My second try at slow smoked ribs yesterday was even better. I used some homemade rub on two racks and cooked 4 hours unfoiled @ 240 w/applewood chunks applying several different sauces the last 30 minutes. They had the bark, the smoke ring and were really tender but not falling off the bone which is fine.I don't think they could have been any better. I've done a lot of reading which really helped me Learn how to control the temps on these grills. Great forum here.