I'm guessing the reason that many have issues is because of the extra emission stuff added to satisfy US emissions .- hoses etc failing from heat / age.
The hitachi carb is a good carb but has been ruined by the addition of all this stuff and is destined to fail.
Had had 3 of them, 2 EA81s (still have Brat ) and EA82 and no major issues apart from messing up a rebuild when rekitted one on an EA82 Had to buy another 2nd hand replacement one. One learns from mistakes made.
Also they don't like being messed with. (and had one EA82 with auto choke - horrible)
Also they have been been ruined by the addition of automatic chokes. These are horrible and need to be ripped off and thrown away as far as possible.
Reason not good for cold starting as they over choke and fast idle not high enough and as soon as blip the throttle - loose fast idle.
Manual choke far superior especially for cold winter starts - can adjust / bend linkages for a better / higher fast idle.
Set all mine to 2000rpm on full choke.
Have seen imported second hand imported US carburettored engines here (Chev V8s) and we shake ours heads in disbelief. This emissions stuff here gets ripped off and thrown away.