Modern Buddy

I took Reptilicus out on a 30 mile cruise on this glorious New England day . I still noticed a particular buzzing noise coming from the engine area. It seems to occur just as I begin to slightly let off of the throttle following a 3/4 turn. If I hold onto the throttle in that position I can keep the noise going.
I can't put my finger on what it could be. Performance is perfect, however. Last week I took off every piece of plastic to check for anything loose, but found nothing except for the handlebars. It's either some unknown part resonating or the actual motor. I wonder if this is something simply characteristic of PGO's 110cc. As mentioned before, It runs great--better every day .
Anybody care to chime in?

I get the same thing. Although, I think I am noticing it less as I accumulate more miles.

Do you think it's coming from the cyclinder? I'm hoping that I'm not breaking it in too harshly. Of course, I really couldn't be much more gentle.

i can no longer hear a thing with the new pipe on but before that i did notice a slight buzzing at 3/4 throttle