mixture,

damh petrols, missing my series one diesel, but anyway,
My 2.25 petrol is running a bit rich, its got a zenith carb which way do i turn it to make it run less rich/more lean,
Cheers

Not sure one way or they other

Great but which one one way? or the other? or anticlock wise or clockwise?!

ah think its clockwise to lean out...

get a weber, they are much easier.

That only leans his wallet

Those Carbs are prone to the butterfly spindle wearing causing an influx of air, most have been mal adjusted to compensate, check a few things first, some have an emissions valve which don’t seem to work( these can be blanked off) , 2nd check the base gasket isn’t leaking in air, 3rd check the inlet manifold isn’t leaking in air.
A simple way to check for air being drawn in, use WD40 spray, spray any suspect area if the revs go up its being drawn in as fuel and being burned.
Before you adjust the Carb, very gently rotate the CO screw clockwise (engine Off) and count the number of turns exactly. Do not force the screw excessively in because the tip can snap off and yore Kn*****.
I can also help you set up the CO using a by ear method if needed.
I also suggest you start back at basics
Correct Plug gaps, Good points, correct dwell angle, Distributor spindle bearing not excessively worn, correct ignition timing, Check bob weights advance, Check Vac advance, distributor cap in good order plug leads in good order.
All above needs to be correct to set up the Carb.
If you need any specific help just ask.

Forgot to add the Webber is an easier Carb to work on.