Sounds like the boot to the manifold (between the carb and the head) might hahe cracked. This will yield a lean condition that will pop at carb and lower your idle. Get some WD-40 and spray around boot with the bike running when the idle changes you found your leak.
2005 1100 Custom
ORKed 5/16" Lines
PODs K&N RU-600s W/PCV
PCS XXX/2 cams
Jetted & PMS Tweaked 20.0/152.5 3.0 turns
Wimmer Machine Custom Oil Cooler & Stash Tube
Dyna 3000 Step 5/ 6500 redline
6" Fwd Control Extension W/Boards F&R
Memphis Shades Bullet Fairing
Progressive 465 rear
Progressive Springs and GVE front
10,000 Monkeys throwing crap at the glass and this one thinks he's Picasso...