Ok, I have this mystery noise at low idle. Sounds like a big vibration rattle. If I bump the throttle slightly it disappears. Sounds like it comes from the top end area, maybe the exhaust header or something. Really annoying and concerning. Has done it since we put it back together. My friend had originally said it could be due to wiseco's .004 recommendation for piston skirt clearance. Engine is 0.5mm over bore, stock stroke, all new bearings and seals, PC pipe, V force reeds, bored carb, running 110 octane gas, 40:1 with dumonde tech oil. 60 pilot, 180 main, CEJ needle 3rd from the top. It runs a little rich, but not fouling plugs. - am constantly checking bolts and am wanting to figure this out. Any thoughts?