Erratic Hesitation / Popping

If anyone is still reading this thread I could use some help.

My 2002 FXDL has an intermittent misfire/carb cough resulting in jerking momentary loss of power under light acceleration through all speed ranges and gears.
Specific conditions:
Reduce throttle a little to coast, then reapply minimal or more throttle to resume speed or accelerate and the engine has a single misfire and falters as a result.

This happens often during the first 20 minutes of riding then, when warmed up happens much less frequently.
Seems to happen more when rpm is reducing around the 2100 mark and throttle is reopened.
Seems to happen more during cool damp weather. Less during 33C(85F) hot weather.
Happens with 87 or 92 octane gas.
Gas tank can be full or on reserve, no difference.
More likely to occur after 10 seconds of coasting rather than 2 secs.
Warm up procedure is:
Fuel enrich full out to start, then idle for 30 secs, fuel enrich to half out to begin driving. Then fuel enrich full in after 10 minutes of driving.

The only thing that prevents the problem is to run with fuel enrich out half or full all the time. It never happens with enrich pulled half or full out.

To my knowledge bike has Stage 1 air cleaner. Unsure of carb jets, but appears to have original undamaged brass phillips head screws holding bowl together, so I assume jets are stock.
Santee 2 into 1 header with a stock FXDL muffler no baffle.
Bike purchased in Florida. Now operating in Vancouver, BC.

Things I have checked:
Idle mixture screw was 2 1/4 out. Changed to as much as 3 3/4 out. Now back to 2 1/2.
Intake leak using propane gas around the manifold.
Spark plugs changed to new correctly gapped. Dealer said they are "burning clean".
Wires appear to be good.
Recently had new stator installed and electrical system checked.
Problem still exists.

The misfire or whatever it is has a snapping/coughing sound unlike a popping from an exhaust pipe. It seems to be near the carburetor and the bike jerks back when it happens like a loss of power when the cylinder doesn't fire.

Again the only way to prevent it is to run with the enricher knob half or full out all the time. After a 6 hour ride with the enricher full in/closed it is less frequent but may still occur as described above. This leads me to believe it is a fuel problem.
I am handy enough to tackle a carb disassembly but only with some certainty it is the source of the problem, ie foreign particles clogging things up or rejetting.

Any ideas on the source of the problem would be appreciated.

Paul