I had the same noise. I pulled my cover and found my idler gear had come loose. My washer and C clip went through my clutch gears and did some ugly things.
Well I guess maybe I'll rip it apart if you guys a serious you think it's the crank. Freaking Chinese cranks that were supposed to be just as good as a hot rods. I guess the wang crank i got lasted like 7 years so i should be lucky.
I hear this weird sound coming from what I think is the flywheel side. No movement in the crank and the seal looks good.
https://youtube.com/shorts/o25XPsmot9A?feature=share