I have no specs. on these engines but I'm guessing you should be ok. You don't see any metal flakes or metalic particles inside the crankcase do you?
That would be caused by a needle bearing trashing on either the wrist pin or on the crank end of the rod.
what you had outlined in red is the wrist pin end of the connecting rod.
You will have some side to side play on both the wrist pin end and the big end of the rod and as sorry as these engines are made probably some circular twist as well.
It looks like either you have a needle bearing wrist pin or else you pressed out the writ pin bushing.
Are you having a problem or hearing a strange noise with this engine?
did you put the same thickenss base gasket on as you took off that will affect the timing of the ports but it should still run better than what its doing now?
On some of your pictures of your engine apart I see somekind of black goo inside the engine. I'm wondering now after hearing it run on the video if you have a mainseal leaking on the crank? something is off and thats for sure. Have you checked you rotor on the ignition side to make sure the key isn't sheared?
It make me think that your needle in the carb has worn strangly out of taper but thats anothe hip shot. You do have a problem though
I'm still wondering if you have the one piece flywheels or the bolted ones?
well there some things to think about.
can you contact your seller and ask him if the flywheels are one piece or is there weights bolted on the flywheel? They may not know and I've not taken one apart with the built up flywheel so I don't know if you can tell by pulling off the head and cylinder. but that shaking makes me wonder?!
You might ask Mr. Dax he might have some insite on this.