Shultz, what smoker do you have? There have been many occasions where the metal "blank" between the fire box and cooking chamber wasn't removed. Tell me what kind of smoker you have, take pictures if you can, and we can go from there. We'll get you fixed up!
i made the suggested mods to my char griller pro right out of the box and im glad i did. it made a major difference. here's the link to those mods. http://www.smokingmeatforums.com/for...ead.php?t=9774
next be sure you knocked out the football shaped end plate where the firebox attaches to the smoke box. the directions for the char griller pro never mentioned doing this when attaching the fire box. When i attached my fire box i also ran some flat stove gasket rope around the opening of the fire box and smoke box to improve on the seal and reduce heat and smoke loss. Lowering the smoke stack or chimney( or what ever you call it) will make a major difference in increasing the internal temperature of your smoke box. BTW are you going by the temp on the factory thermometer? i hope not mine is off by 75 to 125 degrees. My last modification i did on my own, it was to make a stove gasket rope seal around the lid to keep in more heat and smoke. the result? i know burn 1.5 lbs. of charcoal an hour at 250 pretty good in my book! notice my last mod at the very end ot the thread i linked for you.
What kind of thermometer are you using to determine what the temp is? I used one of my buddy's char griller's tonight and he was telling me that the temp. never got hot enough, but he went off of the thermometer that is in the lid, and I had a digital probe on the grate. His thermometer said about 195 mine said 235. I think he is going to buy a diggy.
i use 2 taylor brand oven thermometers (the kind you hang from a rack in your oven) i got them for $6 each and they have a temp range from 100 to 600. ya theyre dial spring thermometers but i dont have to know that im on or off temp by 5 degrees. they work very well and are inexpensive. if they last 6 months then awesome! if they last longer then thats even better. BTW they are 4 months at this point and are still doing very well with an occasional cleaning so i can read the dial.
I know this is a little late for this reply, but I've noticed that you can control the temps to a certain extent by how you position your cooker to the wind. Perhaps the 225* would be easier to reach and maintain if your cooker's firebox was pointed towards the wind. If the firebox is pointed away from the wind, the air travels down the chimney and out of the firebox taking the heat with it. Rotate your cooker as needed to help control the temp.
I have installed a thermometer at the grate level on the door of my Silver smoker on the chimney side. There can be a 40* - 50* difference between both thermometers.