Waiting on my engine from china, I have been watching videos of M series hit and miss engines and noticed a very prominent ball bearing "whizzing" sound...I recognize this is what my roller blades sound made years ago...we would wash the grease out of the bearings and replace with light oil...the blades would be faster but also loud. I made a "Poppin" flame licker engine from scratch and made brass bushings with functional oilers and was impressed with the low drag and quiet run...also the Oilers look cool to! I think the whiz sound takes away a little from the hit and miss sound....just wondering what folks think of backdating the M90 to bushings and oilers....or have folks tried better bearings?....if you grease them they get less loud but heavy grease adds drag that is not helpful if you are trying to slow down the idle and get crazy long coast...as I am...any thoughts on quiet but long coast?