Looking for CO2 adjustment screw

I've just measured the distance between the top of the tube and the screw and it's just over 6cm.
I would ask whoever changed the cam to just check the timing marks and the ignition timing.

The image in your first post… that entire control unit sits on / is bolted to a plastic base and will separate from the larger airbox beneath (out of shot) when you undo the snap on clips I've shown in the images below.

You'll be able to see an air filter sitting in the lower airbox part, there's none in my images.

Once undone the control unit and its plastic base can be raised away from the airbox (which is fixed to the inner wing), though with the fuel lines / rubber hose still attached it'll limit just how far up you can go.

Depending on how much of a gap you can create without stressing the fuel lines etc. you should be able to see the underside of the unit.

The arm with the airflow sensor plate will probably fall open because of gravity as you tip things to one side which will obsure the parts you want to see.

So it'll be awkward, but if you keep the larger arm down you should be able to see the smaller arm within it and inturn a portion of the screw if it's there.

If it's not, the liklihood that the small arm will be able to move up and down independant of the large arm will in itself confirm the screw is missing / broken / something else is amiss.

Read over the post of the 26th, highlights what you're hoping to see.


 

The control unit / base split from the airbox… the larger arm (that the circular airflow sensor plate is attached to) has fallen upwards in this shot, be aware that when it's like that you'll struggle to see the smaller arm / screw.

I managed to get a metering head quite cheap on eBay - I got it just to check how it works - and compare to your photos. Luckily it has the screw in it!

Worst case scenario, if mine does not have this screw I can 'rob' this one.

Great… though that's not something you often read together in the same sentence these days, you'd think there was platinum in them going by some of the asking prices this last while!

Had looked a day or two ago for you and there was a MK2 16v one that might've done, gone now so perhaps the one you ended up getting.

Don't think it'll be the case, but said earlier that the screws aren't all to the same thread pitch, there's a course and a fine type.

If it was that sensor you got then I've not had reason to open a 16v one up so can't say which it'll have… just something to bear in mind in case you inadvertently cross thread anything without realising.

Try not to scrap anything that's left either, all the parts can be useful and you just never know when you'll maybe need something else from it.






 

I'll keep everything!  I asked the person selling it if the screw was there and they said it wasn't. To be honest, if I had not seen all the photos and had the help from this group I would not have seen it either.

Big thanks to everyone - I'll post an update when I eventually get it sorted.