KZ305: cam chain tensioner noise / needs adjustment?

Currently working through the KZ305 as posted a few times about. Since getting the bike, it's made a clunking noise as in the video attached below. I went through the ignition system including the points and valve adjustment (right cylinder was tight) and have adjusted everything within specs. The KZ650 I had prior had an auto-adjusting cam chain, so haven't adjusted those prior on these bikes, but wondering if the sound I'm hearing is a cam chain that needs adjustment? If anyone can give me their thoughts on the sound, that'd be greatly appreciated.

In other news the bike seems to be running fairly smoothly otherwise minus probably needing a few minor carb tweaks. Carbs and the tank seem to be free of  the rust and ethanol gunk that plagued the bike from previous owner letting it sit.

Edit: video link as original video was too large. youtube.com/shorts/2XsDuDE5YpE

On my 82 kz305, there is no adjustment for cam chain tension. The Tensioner is a compression spring loaded shaft that applies pressure on the rear cam chain guide.

So, you are correct. The same shop book has about 10 different bikes listed which some have manual, some have auto. The 1981 kz305a does have an automatic tensioner. Not sure if this is still chain noise exacerbated by something needing carb tuning which is on my list of things to double check. Will go back and check the left cylinder valves again as they were on the tighter side of the span. I didn't come across any vacuum leaks but will check the usual culprits as well.

If anyone has additional suggestions, let er rip. I have looked around to see if there is a replacement spring or a manual tensioner alternative but all old threads seem to be dead or lack of any useful findings.

If you do not have a shop manual for the 305 there is one in the file base which covers the 250 and the 305. It is indicated that there is no adjustment for the tensioner, but it does explain how to remove it and reset it (page 223 and 224). I do not know if this would lessen the noise you are hearing. Will say sometimes if the carbs are not synched strange noised can and do happen.

I have a copy, just the multiple bike models 250/305 has been giving me a headache on the PDF finding things. I appreciate you providing the teardown page #s. Luckily there is nos of the larger spring so a rebuild may be feasible. Regarding the sync, I checked it among other things on the carb but have added it to my double check list along with the valves on left cylinder to just adjust them to middle of spec vs close to bottom of range for peace of mind.