My 2013 (early 2013, not blacked out, no stripes, not derestricted) hasn't done it in a few weeks, 3000 miles. But when it did, to me, it sounded like it had loaded up, (rich). And even now, if I "blip" the throttle on downshift, the idle will drop to 4 or 5 hundred, and stumble a bit before recovering. I'd always refire mine by letting the clutch back out quickly, before it came to a stop. A chirp of the tire, and she'd fire back up. I'm leaning to the "rich" side. BTW, I have my secondaries opened up, but not removed. I'm thinking I want to play with a new tune, closing them back up a bit, but not as much as stock was. I'm overlooking it as a problem, as I love the BEAST. Kinda like Cindy Crawfords mole. You know it's there, but because the rest of the package is so nice, you overlook it! Ha!