I am using castrol gtx which is far better than atlas honda engine oil. i have tried hi octane and i dont think it has anything to do with vibration, no improvements (also only few pumps have that). I also have 1983, and 2007 Cg125 they have little to no vibration like I have in this euro 2 one. Engine wise my bike is okay, just had clutch plates changed (atlas genuine) last month. shoot is great and speed is also amazing just the vibration that annoys me. The vibration is so much that at over 80mph it annoys my hands and shoulders through handle.