I have owned 3 Shovels, 1 EVO and this 1999 Twin Cam. The Twin Cam is my first fuel injected motorcycle. About 5k miles ago, I had my local HD dealer upgrade my bike to a 95 CI big bore. In addition we installed High Performance Cams, push rods, lifters, HD Race Tuner, V&H True Duels, Air Cleaner, and then had the upgraded engine DYNO tuned. Here are my systems. Some days the bike runs perfect, lot's of power, very willing to run. Other days, it will idol ruff and when running up through the gears it feels labored and less willing. Once at speed, the pipes don't have that smooth even sound. The pipes sound more independent from one another and much less even. Sometimes, I can blast the bike up to 4,500 to 5,000 RPM and the bike will smooth right out. Any ideas why? Could this be a bad injector? The bike has 88K miles and is equiped with the Magnetti EFI system. Thanks for your help, David.