Just checked the CO% reading at idle, about 1000RPM and it was about 6 to 7% CO. We can get the CO reading well bellow SVA, Mot standards but it runs pretty rough. At the moment it is set up for performance rather than emissions but it just seams high. Is this reading normal for well tuned carbs?

7% is very high..

we failed an MOT at 4-5% CO on bike carbs on our 2.0i pinto..before I realised I had clipped the starter enrichment plunger constantly open.

high CO means too much fuel for the amount of oxygen in the combustion..

Try to go a leaner (it must smell very fuely), the idle problem might be due to a timing issue contributing to poor idle, not soley a fueling issue. Worth checking.

my 1800 zetec on dellorto 40's idles at 650 rpm, CO about 3-4% Very sweet too.
Sounds like jetting is off on the idle circuit.
Guess you have 50 or 55 idle jets, f9/f11 air?