Fine Tuning a 360 Magnum with a Brawler "Double Pumper"

Got some pictures will post them in just a minute but I just stopped at work after setting the t slot to be a square, and timing is still the same at about 18. My idle is super high, was at 1200 when I was driving and it dieseled like crazy when I shut it off. Should I back off the timing slightly? If I close the idle it won’t show any t slot anymore, and it’s backed off basically all the way. To show the t slot it’s half a turn once the screw contacts the arm
How “closed” are the secondary butterflies? If they’re open at all I’d close them to lower the idle. Then I’d retard timing. You can move the primary blades around a little but you want to keep the T slots fairly square.
Edited to add;
The secondary idle stop screw is almost always buried under the baseplate and not easy to get to. But it is there.