I went to look at a blackbird today and noticed a bit of mechanical/ geary/ grumbling noise when I let the clutch out in neutal on tickover. Is this symptomatic of somthing or just noticable because the rest of the engine is so quiet ? it's done about 21k, BTW it's up for 2900 and is a carb'ed one. I'm tempted but only looked at one so far.