I have about 2500 miles on my 2007 Nomad 1600 and I have the same noise that others describe. Roll on the throttle in any gear and there is engine chatter/rattle once it is over about 3000 rpm (I have a tach). I also have a bit of backfiring when you release the throttle. I also run premium gas. I tookthe biketo the dealer and they took it for a test run. They told me that the chatter and backfiring is not a serious problem. They figure the bike is running a bit rich, which is the cause of the backfiring. They explained that the ECU is mapped atsea level and that because I ride at about 3500 feet elevation, the bike will run rich. I don't know if I buy this explanation or not. They said to just keep riding the bike, it's nothing to worry about. I don't know if they were just trying to get rid of me so they do not have to do the warranty work, or not. Anyway, I don't think a brand new bike should have chatter and backfiring. I have decided to put on a couple thousand more miles to see if it gets any better or worse and then take it back to the dealer.

Is there anyone else out there that has experienced the engine chatter noise and mild backfiring? What caused the problem and how did you fix it?

Thanks alot!