Purchased a 13 Road glide about a month ago from local HD. The bike had 6k miles on it and has been tuned at that HD with mastertune 2 and also has V&h power dual headers with v&h monster round mufflers. No other mods to the bike. My problem is that it has a noticeable ping (like a spring jumping around ) when I'm at WOT and above 4000rpms. Took to dealership and they rode it 10 miles after it was cooled off and said they can't duplicate ping. I believe they can't duplicate it because it only does it when at WOT and above 3800-4000 rpms and they probably aren't pushing it to that. What to do next?? Tuning issue?