i just found this in something called BBQ.COM...you can take it for what it is, i do not know for sure...but sounds good...
The smoker consistent temperature for the duration of the cooking time is very important. Now this isn't as strict as it would be with more traditional barbecue, but consistency is important. You can smoke your turkey anywhere between 200 and 275 degrees F. I recommend staying above 235 degrees F, to control bacteria and reduce the cooking time. There is no real benefit to cooking at a lower temperature than that. You can cook at a higher temperature but anything above 275 degrees F, isn't going to give the smoky flavor and tenderness you would want from a smoked turkey.
This is where your smoking experience is going to pay off. Your turkey will cook slower at higher elevations and weather will play a big role in the cooking time. The type of smoker used also changes times and temperatures. Because of this, all I can offer is suggestions of the cooking time. You may need to adjust the cooking temperature up or down to hit upon your dinner time (also plan on an additional 15 minute rest time before you carve).
At 235 degrees F your turkey will take 30 to 35 minutes per pound.
At 250 degrees F your turkey will take 25 to 30 minutes per pound.
At 275 degrees F your turkey will take 20 to 25 minutes per pound.
i see nothing about the "140* in 4hrs" rule, so keep that in mind...it is also my 1st turkey in the smoker, so i was wondering the times also...good luck...
smoke on, eat strong!!
mosh