Click on top engine

Hello all,

I'm looking for a click sound. I just finish to rebuild the engine with new gears, endless cam chain, valves leak check, shims on spec, and i have this click sound on the top of the engine.

Any good idea is very welcome 

youtube.com/shorts/3AnzUUdTkSo
 

Have you  balanced the carbs 
checked timing .
adjusted cam chain tension
Dave

Carbs are sync.
Timing is good on 0 then 1 to 28 at 1/4 tdc.
Dyna timing checked and fire at F like it should.
Chain tensioner set at 1/4 tdc. (I ever try the manual tensioner with same result last year)

I rebuild the engine to search for this click. That's why i replaced all idle gears and the cam chain and check for any leaks on exhaust, plugs...


 

Is motor stock ?
Cams ?
You might think I'm crazy  , but are cams rubbing the cam cover .
It happened to me and I just doubled up the gasket. 
If so there will be  marks inside cover

Engine is stock. Thank you for the idea but the cams don't touch the cover. There is no marks inside.

 

Have you tried a mechanics stethoscope (they are cheap on Amazon) to pin point the noise ?

To me, that sounds like cam chain noise (loose).

Have you disassembled / rebuilt the tensioner?
I had similar "noises" until I installed a manual tensioner.

H.

That tinny clicking is metal against metal in time with the cam rotation on the inlet cam. 
If it reduces in volume as the engine warms then it's something that is expanding with heat reducing the gap. 
If it doesn't reduce with heat then it's something which remains constant or is loose. 
Reduction with heat I would suspect a worn bucket/head interface. 
If it's ever been starved of oil up the top then the bucket will wear the head bore with the rotation of the cam causing the bucket to rock front to back and clatter against the head bore. As both the bucket and head heat expansion will reduce the gap and reduce the clatter. The fix is to use a Suzuki bucket which is fractionally larger diameter then redress the head/bucket interface. 
If it doesn't reduce with heat then it's cam/bucket interface. 
Either the cam gap is way too big or the cam cap/shells are loose/worn allowing cam shaft flex causing lobe slap. Checking with plastiguage will tell you if shells is the cause. 
Loose or worn cam cap threads/bolts allowing the cap to lift will also cause lobe slap. 
 

When i rebuilt the engine i find that the tachometer gear was bent. So i remove it to be sure it was not the problem.
can something other than this small gear was bent too ? Like… the camshaft or more… the bearings …

The Tach worm drive is on the exhaust cam. From your video it is the inlet cam area that is makeing the noise. Having just listened to it again at a push it could be a sticky /bent valve stem causing the valve to snap shut.
A compression test on that cylinder might tell you something. 
 

Oh oh … i was looking the cams and i just see that in fact my cam chain is grinding my cover ( thank @ street fighter ltd) 
…worn rubbers ?

Post a picture of your head without the cam cover on. 
your idler sprocket should be holding the chain down in the centre so the cam chain shouldn't be that close to the cam cover. 
So if your idler is as per the pic below the cam chain should well clear of the cover. 
Assuming you have a cam cover gasket fitted you could double it up or file a bit of clearance in the webbing.