Engine Noise

[Timmy250]

Yep, I had exactly the same concerns, my first single Duc ('62 Monza), brand new top and bottom ends, when I first started it, thought for sure I had mis-measured or badly assembled, went through it all again, and really nothing appeared mechanically wrong, just the noise. I have never personally heard another one running, listened to some videos, and heard similar sounds, so, now have gone through several tanks of gas, all seems well, it just makes that sound. But, as you say, it's not temperature or throttle dependent, just seems to sound that way. So, I stopped worrying.