That’s true but if it’s worse then I would buy all new correct mikuni brassware everything 

Yeah my thoughts too #120, but maybe we're all getting crosswired over the problem haha.
Myself i'd try droping the needle in to the bottom with no clip & see if it runs.
But maybe ignore that & just block the main jet with something.
Be lucky then if it will keep running 'except on choke' on a mostly closed throttle or theoreticaly on idle only.
A test i'd try even though shouldn't be neccessary.

If you've done and checked everything you've said I think it's time to swap ignition. 

I know it doesn't seem likely but it really seems to be electrical to me at this point. 

I might yet have to 'eat my hat' but just played the video again on page 5 to hear it clear about 3 seconds before it runs dry guessing fuel was off at that stage & running dry in the bowl. I dunno, 13 pages & still chasing it. Must be nearly there.
www.youtube.com/shorts/MAfxS2-HXWE

Checking timing with a strobe light, is fast and easy to do. It also provides a visual indication of whether there are any major issues with the ignition.

Haven't read through entire thread so forgive me if I'm repeating something.
If you start the bike up when it's dark, with the mag cover off have a look to see if there is excessive sparking around the points.
There should be a few sparks at tick over but less at higher revs.
If you're seeing lots of sparks, then I would suspect the condenser isn't doing it's job.
Just a thought, hope it helps

If its running overly rich, to the extent it wont rev, then I get the feeling it probably wouldnt even run?

But if the problem is a very rich mixture, then running it until the carb is just about empty of fuel, will mean it momentarily runs ok before stopping.

If it's rich due to ignition problems, in my experience it may also rev when leaned out/running out of fuel. 

Timing strobe used on Terry's MX175 ignition, which had a very regular misfire and as a result sounded like it was "four-stroking" rich, did not reveal anything....  (pretty hard to count if strobe is flashing 25 times per second even at only a 1,500 rpm idle.  At least I can't do it.)  I also used a scope on Terry's ignition while running and not running (spun engine with a drill motor).  Bike started first or second kick and had a very regular spark, just would not rev.  It would rev clean for a second when carb was running out of fuel though which reinforced the idea that it was too rich.

I already posted my video of the 3 ignition comparison.  Below is one of Terry's original videos from several years ago.  We all initially thought it was simply too rich.  It wasn't.  It was ignition. 

I agree it's a longshot, but it seems you've tried everything else multiple times?  Since you have another ignition on another bike, it seems worth a try?   Also I don't remember if you installed a "new" ignition coil?  Many of the aftermarket ones are no good from experiences posted here.  Maybe start there.  Swap the plug cap if you haven't already and make sure you aren't using counterfeit spark plugs. 



 

Is there a risk with dropping the needle in the main, seems like its slightly possible to get it sucked into the engine. Either way I am planning on swapping the ignitions as it is easy enough to do and like MarkT said I have another one laying around. Planning to do that this weekend. I have the OEM ignition coil and haven't bought any aftermarket (speaking of I cant find my rt3 coil). But my RT3 ignition system looks to be in better shape as well. I have changed the caps though and there was no change there. 13 pages and counting, itll be fixed by 15..

If you don't have access to a strobe light, the only way to pin down an ignition problem, is to fit the complete system from a bike which is running well.

Unless there is a want to restore your bike to totally original condition, fitting a new Nibbi carb would be a very good idea, and will eliminate any issues with 50+ year old, worn out OE carb.

If yours is a flange mount carb, fitting a more modern spigot mount one, using a rubber manifold adaptor, will in itself help to improve carburation.

Nibbi Keihin clones, are very easy to set up, use genuine Keihin parts, and if your problems are carb related, will sort them completely in less than 30 minutes.

A strobe light, and a spray bottle of petrol, will easily determine if your issues are related to ignition or carb, but using the other methods suggested here, will work, just take longer, and may well mean going over the same ground repeatedly, if you have a bad carb for instance, and get involved in repeatedly stripping and rebuilding it.