Thanks for some feedback Andrew. That's pretty much how I did it. The smokenator on one side loaded with charcoal - about 15-20 lit and the rest unlit (minion method) and a couple small chunks of apple wood. I put the spatchcocked chicken on the grate for indirect cooking with legs facing the heat source, water pan over the smokenator, pretty steady temp of 300-325 and after 4.5 hours, still not done. Another 30 minutes on the grill, 15 of resting and was still not totally comfortable with the results.
Your setup here is perfectly fine......one thing from the 1st post that stands out to me though, is this:
"kept relatively stable at approximately 300-325º on the
dome thermometer"
The dome reading will always be higher than at the grate, sometimes by 40 or more degrees (fh) and.....if the therm is not completely accurate (which these commonly are not), then that difference could possibly be even more.....
Half chickens or spatched should be done in a lot less than 4.5 hours it
SEEMS.......I could be wrong, but that thick of a piece just seems, at that temperature like it would take closer to two hours, if that.............
Like said, I could be wrong as I don't get to do a lot of whole ones as the wife gets ahold of them & does them in the oven (very well, but still!!) .................so, humour me.....
Here's some possibilities........
Try lighting more coals at the start, like double the amount......
Get the pit up to a high temp, like 400f.....good & up & running before the meat goes on.....
Put a can lid over the dome therm if you're tempted to look at it.......
Get a cheap grate therm, like this:
Take a reading after 25 minutes of hot charcoal heating the kettle, lid on, vents open.....
...........at Meat Level (<<< Technical Term), then set your chicken on, cap the bugger & cook.....
Try top vent open, bottoms 3/4 open to extend your burn time a bit......
Don't lift the lid for a hour if you can stand to (kinda makes you trust your setup in the first place, eh?) then see what it looks like & perhaps take a reading with an instant in the thigh / leg & see where it's at........& if you have at least a decent idea of what previous ones looked like on the outside, charcoal or gas, then check how that compares......likely it will need to go more, but I think it will be much closer to done than previous ones at one hour......the grate therm should be plugging away at 350f if you got a good solid burn going at the start......
Hope the logic makes sense.....get it going good & strong, contain the heat well by not looking, trust that you set up well, check quickly with an instant read & I bet it gets good & done much sooner...............
This is a set for a chicken pieces cook....granted, not like whole bird..............
....but it did not take very long at all starting at this temp:
525 degrees......
You could also test out different sets....here's one MacEggs from Canada did.....
Here's what he called a "fail"....two chickens on an 18" Weber, 30 degree weather, an hour & fifteen minutes & they were 'close' to done.....
http://weberkettleclub.com/forums/grilling-bbqing/beer-can-chicken-experiment-fail/msg90633/#msg90633