Hey Brian - I can't comment on the 1200 Nightster but I had a 2006, 1200 Custom and traded it for 2007 Heritage Softail Classic and like all Harleys, they don't come broke-in. Just treat your baby with kid gloves the first 500 miles and especially, don't stay at one speed for long periods of time. Riding at different speeds allows the piston rings to seat properly and will result in better gas mileage in the end. I know it's tempting but don't "get on it" to see what she will do until you exceed 500 miles and then be careful doing that until you accumulate 1,000 miles. As the last gentleman stated, if you hear something that doesn't sound right, get her to the shop immediately. With proper break-in your baby will last a long, long time and will provide you with many miles of pleasure. Just remember, even the worst day of riding is better than the best day at work. Take care and enjoy. . . . . . .Bruce