I have noticed that my '91 (carb) Electraglide stutters briefly about one minute into each first ride. After that...sweet as a nut and no missing. I starts fine and I warm it up for about a minute. I do turn the fuel tap off at the end of each day. The stutter is similar to a running out of fuel feeling but doesn't last long. I am wondering if this an air lock working its way through because I previously had the fuel tap off. Any ideas on this?

takes a while to warm up , give her a little choke for a while . better still  clean da fuel tank & carb out 1st & seehow she goes , allway turn fuel cock off

I know this conflicts with what daddyracer says (and I always respect his wisdom on things Harley!), but I experienced similar symptoms as you describe them and solved it in a different way.

I found that if I used my choke (enrichener) for too long (more than 10 seconds or so), my bike would splutter for the first few clicks or so, then come good. I now use the 'choke' long enough to start her up, then baby the throttle for as long as it takes to idle (30 secs or so) and I have no more problems.

My plugs were also a bit sooty, so I guessed it was running rich and tried the above method.

on;y use enough chocke so the engine runs good bring it back untill it splatters then add a bit , never over choke any engine , you will dirty spark plugs then they will clear

I use full choke on my cold old Evo to start her up and then within 20-30 seconds I'll push the choke all the way in and use the throttle lock to keep the engine at a faster idle until she has warmed up. It normally takes 5+ minutes for her to warm up enough to give me a flawless ride.

I only ever use the choke for the first start of the day....or if she has been parked all day at work.

don't let her sit around warming up as the top end will over heat ( exh valves & guide's are da hottest part of da engine ) as no cool air cooling da fin's down,   no more than 1 min max then ride slow for 3-5 klms, 

feel the oil tank that will tell you if she is  warm-up or not