I recall my auto shop teacher used a compressed can containing a gas of some sort to chase down vacuum leaks. The light gas was fed through a clear tube to a  specific place on the engine. If there was a leak the engine would race. Granted the practice was setup for 4-stroke automotive engines but wondering if this would have any application for these 2-strokes. 

Just  a thought . You've not mentioned anything about the bikes history .
I 'm wondering if you or a previous owner has installed a carb kit , like Keyster .
Have you checked all the jets are Mikuni and the correct size , and needle is the correct component .
That is often the source of poor running , and you could clean the carb until  " the cows come home " ,
and it won't run any better .

Swoop,
dad was the original owner. Jets labeled with the stock numbers. I don't think he ever did a carb kit. The numbers match what is supposed to be in there per spec. 

It would be nice if you could post a video with sound of the problem, not just idling.  It doesn't matter what the camera sees as much as the sound.

Did you say you replaced the condenser?  On the 1979 thread you said your bike sounded like that one and that one sounds like ignition issues to me.  Bad condenser can cause quite a miss.

 

Have you had the timing cover off ?
If so did you notice any fluid in there ? Could be a crank seal ?
have you tried spraying WD 40 or similar around the insulator on the reed block ,base and head gasket ?
Have you tried running it disconnected from the air boot completely? Maybe try doing that and squirting a bit of fuel see what happens .Just a little spray bottle and a squirt in the carb mouth see if things smooth out. It sounds what i would describe as woolly in the video.
Are the reeds free or there at all ? Possibly corroded stuck closed. The materials they're made from would suggest that's not really possible but it's worth a look.
Just a few suggestions.

I snuck a peek at the reeds sat. They look good. No light. They flap nice.

Back to school so kind of wiped out but I will try get a video up either tonight or tomorrow...

I am seriously wondering about a slipped flywheel key. But idk.

Lots of good ideas Thank you all.

I'm surprised i've not suggested flywheel key but 'hadn't played the video till now' & "Yes i think so", or points 'barely visibly opening'. Sounds retarded & sort of lean. Often crank key breaking ends up with flywheel advance & kicking back but not necessarily so. Hell i usually say crank key even for a flat tire lol.

Mr. Rt325... I enjoy translating yer conversations.. You are a very knowledgable.. "able to make a silk purse out of a sows ear".. kinda fellow.. 
I'm hoping for many more years of yer insight! Among many others too!
Sneezles61

Thanks Sneezles, we're all trying to help if we can & i don't always get it right. But i so admire the guys-- '& Gals'-- that make a 'better than showroom' job of restoring, just mind boggling restorations going on. I just don't have the patience or skill--& cost of shipping things out like painting & chroming would give me ulcers--which i already have lol. Hats off to all of you.

Yes thank you all the tips and ideas are all welcome. I'm going to see about the flywheel key after school today