A short video.

https://youtu.be/D-KQ9SWD6tc

says this video is private
can't open

I think now is public... sorry about that.

And here is with cover taken out.

https://youtu.be/AuZteU8dzGs

I think i have a lemon 

Sounds like the paws or springs are fried. I have seen this before, your gonna need to open it up.  Time for surgery.

I think so too. But the UTV has 2 miles. Never drive it. Never left my garage. One thing is for sure...
Design:  8.5
Performance: 8
Built Quality: 8
Quality Control: -1

This thing came from factory this way. 1000 employees and no one heard that?. I dont think in 2 miles, wich i never drive, because my dealer was, could fried the wet clutch or a bearing, probably this is a bad dream.

[2015 Z Force 800 53/Trail EPS]

Mine makes some of that noise like the first video but goes away after it warms up. It's done it from day-1. Vid#2..that's a different story. Still wet clutch or oneway related like Bprain says I thing too.

I hope I'm wrong, but it sounds a lot like a main bearing. What ever it is, warranty should cover it.

You mean crank shaft bearing?, if it is, thay have to split a brand new engine, that would be terrible. I dont want a 2 miles open engine. So, if they have to open it, i will gently ask for another 800, new, like this.

Or talking about one way bearing?, im prety sure is not an engine problem, is a transmission isue, because it twist by hand primary clutch and make that noise, you cant turn your crank that easy.
Beside warranty, here in Argentina, Zforce 800 arrived last week, yes, waiting them for 4 month, so there isnt any kind of parts for a major rapair. So, im scruwed up.

I did notice the primary spin off and on in the beginning of the video than stop. I would guess that the wet clutch  was dragging a little bit before oil coated it. If I was in your shoes I would put it back together and bring it back to the dealer and have it checked out. It's under warranty, this is not your problem. It should be his.

Crank bearing is what I meant, but if you can turn it by hand and make the same sound, it's probably in the clutch. The crank would not turn easily. You'd have to turn it against the compression. If you can turn it back and forth just a little because it has some slack and make the sound, it could be a rod bearing.

In this two videos, its almost clear that is the wet clutch or a faulty bearing. Not seem to be a main bearing or a rod, because engine is not running in one video, and in other i can recreate that sound, and it ¨calm down¨ by twisting  the primary.

https://youtu.be/9Im4HdASf9o

https://youtu.be/NVCNtES8W2o

[2015 Z Force 800 53/Trail EPS]

Yeah, clearly it's wet clutch related. Also remember that outer bearing on the cover is to help align it...especially under load. I'll bet you can grab the shaft-end, work it around and have an effect of the sound. With the preload on the belt I would almost bet if you pulled it toward the back of the machine the sound even may disappear.

My theory is, that one spring of the wet clutch was faulty, so one pad was fried, and now its hitting clutch case. ill keep you informed, when my dealer check it.