Sorry for underestimating the Beige Beast's vintage, as it's a 1975 build, going by the engine plate...
Those carbs usually have a small screw plus lock nut for the basic 'tickover' setting, which can then be fine tuned using the air volume screw.
Iirc, you want the air volume screw to be 'about' one turn out from fully home, then adjust the throttle stop screw.
After altering the air volume screw, the idle mixture screw on the front of the carb usually needs a tweak as well.
Depending on the mileage the engine has covered, the secondary throttle stop screw may need adjusting.
That's the one visible in your picture, pointing upwards, with the stop touching the head of the bolt.
1/2 turn inwards on that usually helps, or at least does no harm.
Is the primary petrol jet a 'grub screw' type, or similar to the secondary petrol jet?
Most probably the former, in which case you need to remove it to check what size it is.
If it's a 120, I'd advise going 2 steps up, to a 125...
ken.
Nelsthebass wrote:
Hi Ken
No Pics as too dark when I read your post - The Beige Beast is '76 vintage and has an organ pedal + rods to activate the throttle
You can see the carb on
download/file.php?id=2486&mode=view and can see the aformentioned air volume screw in the top left