Marbles?

[Freddy Snottgrass]

I don't have much experience with small engines and this is my first MB. When my engine is running I hear what sounds like a marble spinning around. Kind of like spinning one in a spray paint can. I always hear it when the engine runs. When I pull the clutch as I'm going down hill I can still hear it, but if I shut off the engine it stops. I assume that eliminates it being something in the chain, clutch department since those are still spinning at full speed. Is that just a trait of the engine or do I need to start inspecting things more closely?

 

[JerboaJohn]

might not be good, but also could be simple. pull the right side cover and see if anything's loose or in there. then take off the head and look if the piston was smacking the plug. what you hear could be pre-detonation too. that happens when your carb is too lean (usuallty) or timing issue (not likely)