Hi im pritty new to the 300 scene
Got a 1.4 on a webber twin barrel
The issue is when one i put the choke in
It starts sweet but drives crap once u put the choke in then pull the choke out and drives nice. cant find any air leaks do u rekon it could be the rockers need a tweaking coz they have a slightly noisy tap to them or is it going to be a intake issue?

Also getting a faint grind from the rear of the engine what do u lot rekon it may be?

If the tappets are noisy then I'd adjust them as first step.

That would sort the irratic idle
But it also has a little power loss when i pull away that would be a air leak in the carb or a mixture issue

It's an engine with a manual choke after all, and they can be a bit picky when running cold. I know mine is, even though it runs quite well when warm.

Start it with full choke if the engine is fully cold. When you start driving, push the choke in a bit, whatever feels right so that the engine running feels right. You'll learn it by experience. Now, when the engine warms up, it'll need less and less choke. On mine I can push the choke fully in when the temperature needle has moved just a bit to the right, maybe 1/5 of the scale. I currently don't have that "space age tube" for pre-heated air intake (it fell off in pieces), so it needs the choke for slightly longer in the Finnish winter.

Whatever you do with it, do one thing at a time and check in between whether it had any effect on anything. But I too would suggest adjusting tappets first. Then mixture, and if that doesn't sort it out, start looking for other reasons, like air leak between carb and intake manifold, dirty carb jets, ignition, ...

If the exhaust tappets have gone tight then you would have compression loss - could be the issue.