Lousy Idle

New member here, hoping for some guidance.
Replaced rear head gasket on 99 FLHT, and bike runs flat. Black smoke at cold start-up using enricher, gas mileage down, and plugs fouling. Replaced plugs, checked ignition wires, even tried another carb, but no change. Did not check ignition coil yet, but do not think the problem is ignition components. Could it be MAP sensor, and if so, how do I check it?
Thanks in advance for any help.

sounds like maybe a vacuum leak. with the motor running carefully spray some wd40 or carb spray on the intake where it connects to the head if the motor changes theres your leak.do it from the primary side good luck

Thanks for the input, but I already checked for an intake leak. That was my 1st thought.

try pumping the throttle once start the bike without the enrichener and use the knob on throttle to run it at a fast idle If you run it for any amount of time with the enrichener out the plugs can easily foul

Tried all the standard carburetor and ignition solutions, but still can't get it right.The bike will run without enricher after warm-up, but performance is flat, and gas mileage is down. Will not get full high idle with enricher on (1200-1300 rpm max) and blows a little black smoke. Still think it may be MAP sensor, but don't want to spend $50 if I don't have to. don't have any previous experience with CV carbs, but don't think they can be that much different than old KEHIN.
Thanks for trying.

If it wasn't running this way before the head gasket replacement, the odds are INCREDIBLY high that the problem was created during the replacement. Get a good vacuum check on the whole 360 degree head gasket. Check for anything else you may have crunched, gouged or otherwise messed with while accessing the head.

The good Lord knows that I frequently create problems when I "fix" things, you may share in this curse. Good luck!