It can mean that you're running slightly rich on the LSN and the idle gap is too wide... If it's a lean idle, generally it will idle high and the exhaust note will sound fluffy.

Best way to check LSN setting IMO is the punch test... Get it warmed up to running temp, drive a couple full throttle passes and then bring it to a stop and idle it for 10-15 seconds and then punch the throttle and observe how it responds...

If it takes off sluggish with a burbling sound and lots of smoke... It's too rich
If it bogs and hesitates on take off with little or no smoke... It's too lean
If it accelerates rapidly with a crisp clean sound and a good amount of smoke... It's spot on!

Once you've got the punch test right, then reset the idle speed using the idle stop screw and recheck the punch test... Fine tune again if neccessary...

The LSN and idle gap settings are a bit of a balancing act and can take a little bit to get right but once you find a method that works for you, it becomes quite easy!

Just my $0.02 But it works for me