Greetings gentlemen,

Here I have my Honda cbr 125 r out of 2015.

I have bought this bike in December and have rebuilt the complete engine with new ball bearings, new crankshaft new cilinder new piston, and piston rings etc. Also a new piston pin. 

After rebuilding the engine ran fine, performance is great for a 125cc. I have driven around 200km on it.

But then I started hearing a ticking noise, which I couldn’t really place. I have setting the valve clearances which didn’t fix it, I have replaced the cam chain tensioner (the chain was already new) the timing and everything is correct. Eventually when I took the camshaft holder out, I noticed one of the valve clearances stems was losing a bit of thread, aka it was bad, so I replaced both with a new locknut. And set the timing, the ticking seems to finally be gone. 

However when I rev it to around 4-5k rpm as you can hear in the video it rattles, and I am completely stumped as to how I can fix this/what the issue is. Initially I thought the rattle was because of the valve clearances or the cam chain tensioner, but both are correct/new.

Does anyone have a clue what could be the issue? Or is this some placebo, as I am quite new to motorcycles.

P.s. the smoke in the video is oil on the exhaust, I spilled a little.

Honda cbr 125r 2015 jc50/jc39e engine rattling when at 5k rpm