Hey guys!

I have a 1998 year model 650ls savage. 30K km on it.

It is my first bike, been mine for couple of months now. Ive been lurking here for information for my bike, cause I want to keep it for long term and take some good care of it.

Latley Ive been noticing some ticking noise, so I thought that Ive to make that notourius cam chain tensioner mod. Turned out, previous owner have already done it.

So now Im wondering what makes that ticking noise then? Do I maybe have to replace the chain still? Or is it maybe something to do with valves? Or is that little ticking normal for savages?

Here is a link for the video- https://streamable.com/zb8o0j

The design is ancient. In perfect adjustment, the valves tick. Get rid of the tick, they are too tight. So, if it sounds like a sewing machine, mehh.. It's okay.
It's probably a good idea to check the valves. You already checked the chain, just Knowing where you are with it is a good idea.
Book says 5,000 miles/adjust valves. At 5,000 miles I paid a mechanic to do it and let me watch. They needed it. At ten thousand, they needed it, but at fifteen, the pointy ends of the adjusters had flattened and hardened and they were only slightly in need of any adjustment. Still in Spec, just not optimal, imo.
We all know how important a Coupla thousandths of valve lift is. It's at Least twenty horsepower.

Your engine sounds great to me.  May I ask what you used to make the recording (phone, iPad, GoPro, etc.)?

To the naked ear, mine sounds just a bit louder.  I have some piston slap (result of a prior seizure), but the general tickity-tackity stuff is similar to yours.  When I record the thing with my iPad, it sounds like it's comin apart at the seams.  So much so that Verslagin suggested I check valve adjustment.  I did and all four were right at .004".  As I mentioned, if I just run the thing in the garage and listen with my naked ear, it's very quiet.  Similar to yours.