Amal mk2 single carb jets

First check that you are operating the enricher correctly ie lever up is off and is it functioning correctly , the small black seal can come adrift and disappear. Check the air screw is between 1.5 to 2.5 turns out.
From memory the jetting is, Pilot jet 15,  Needle jet 107, main jet 160 rings a bell. Slide I used was a 3 but others use 3.5. The standard alloy slide will hang up, you'll need a stronger spring or a chromed brass slide that's expensive so make sure you know the size you require before going down that path.

Also be aware that the carb settings are the same regardless of whether you have one or two carburettors.  So the book figures for the original twin carb setup should still apply.

Chances are the needle jet is worn, so a new needle and needle jet is a good starting point. Bear in mind there are several jets at difference openings, which one is causing the sooting (won't be the main jet which doesn't wear)

Hi Andy, I had trouble with the lever choke system on the Mk2 Amals not seating properly after a few months use and causing rich running, I changed them for cable pull type and had no further problems.

Hi, I run the 34mm single MK2 on some of my Commando's for over 35 years and these are my settings.
Slide is No 3, needle position middle of 5 settings, 106 needle jet, 260 main jet and I also use the chrome brass slide. My mixture screw is usually between 2 or 2 and a half turns out.
On another of my Commando's I use a Mikuni 34mm which has similar performance.
I prefer the single carb set up as the bike always starts easy and ticks over all day and is easy to maintain and clean.