hi
not sure about this issuse but i have looked at other threads etc about blocking a air bleed screw off just next to the trumpet as if you dont it can run to rich or to lean is this true ?
i have tested my car and its to lean on tickover and at about 3000 rpm its about 6 % co could this cause the issuse
any info would be great

The air holes you are talking about have nothing to do with tick over revs CO's
to adjust the fuel at tick over its the air screws
The holes come into play at higher revs
The best and only safe way is to have ti set up on a rolling Road
Bogg Brothers are not to far from where you live for this
Jacko

You need to speak to a bike tunner. Someone who has modded bike carbs. Boggs are ok but there is more to setting them up than boggs do.
One thing that does help setup is a dynojet kit. In the kit for the carbs are all the bits to block the aircorrectors and adjustable needles.

My zx-9r carbs were very lean at idle and power. just blocking the aircorrector holes improved things but still needed bigger main jets.