1930 Big 4 'Normal' engine sounds????

So, I've finally got my 1930 Big 4 on the road.  I've taken it for a couple of shakedown rides in my local area.  Really enjoyed myself.  First ride I broke down 3 times and identified a petrol starvation issue.  I'd replaced the cork seals in the petrol tap and a little fragment of cork had lodged itself in the hole in one of the cork washers partially restricting flow.  Pain in the behind but easily rectified.  Just got back from my second ride...faultless!  I need to learn some techniques for better riding.  One that I read about was adjusting (retarding) the ignition slightly to slow the idle speed when in slow moving traffic.  This worked a treat.  As soon as I got moving I fully advanced the ignition.  First question is, is this the right thing to do or should I adjust the carb to a slower idle?  The idle speed seems great when I first set off, it was only when the engine got properly warmed up that it seemed a bit racey on closed throttle.  Any other tips, tricks or advice regarding the ignition postion during riding would be greatly appreciated.

Question number 2.  Everything about the bike seemd fine, gear change, clutch operation, a little blue haze from the exhaust.  The only thing I did notice was a noise from the upper engine.  It occurs when in gear and moving along when the throttle is close to or properly closed....so really when I was coasting to slow down a little.  The closest thing I could describe would be the type of sound a kick starter makes that has not returned when the engine fires up.  So a kind of 'rachetty' sound.  Let me stress, it wasn't as 'metalic' as a kick strater...it wasn't alarming and it didn't sound as if anything was grinding as such, but it's a sound I've not heard before, this being the first bike I've owned from this era.  I'm guessing it might be the valves or push rods or the like???  The sound didn't happen when stationary or when accelerating.  Does anyone have any views on this matter?