TOPIC:

Your answers do not put me in trust. I will try to communicate with the previous buyer to know what have been done. Check everything, again. I do not want to go further because I'm not comfortable with timing and I'm not rich at the moment. But, my dad have 2 other complete engine so if I must dismount all the engine and go back, I told myself that there will be a good reason for or that it will not be necessary to rebuilt if it all good, but I the worse case I have the parts in triplicate. Let you know what happen with my 1300

I think this is the right direction. There are not many other options. If you investigate and find nothing, ask the previous owner and find nothing, the options are very limited. 1 - close it all up, fill up, cross fingers, press the start. 2 - remove the engine, disassemble, rebuild, install. 3 - remove the engine, replace with a spare. I am with kawboy about being very nervous about the option 1. But based on the engine running quiet after the last try, finding all the pieces neatly at the bottom of the oil pan, if a further visual inspection will not show anything, keeping in mind the option 2 and 3 and what they involve, I'd seriously choose option 1. Check that all is moving free turning the engine by hand. Remove, check, replace the oil filter. Check the coolant. Fill the bike with new cheapest oil, run. Do 50 miles if all is quiet, drain the oil and check it. If all good - fill with good oil, and ride. IF shit happens - go to plan 3 and swap the engines. You will have a good running bike, if the engine is good, and all the time in the world to disassemble and investigate.

That's my last 2 pesos for the moment. I am really curios how this story will unfold. Keep posting updates!

My gut instinct says that the cam chain tensioner bottom roller has disintegrated. The black plastic like particles are from the roller and the metallic bits from the needle bearing / housing underneath the roller body.
My roller broke down a year ago and I had to replace it, the mess in the pics looks very similar.

My gut instinct says that the cam chain tensioner bottom roller has disintegrated.

I agree with you Lare at this point. I think Idemon should revisit checking the engine from the top. We mentioned before the tensioner and guides, and he said he checked all after removing the cam cover and all looked good. But it makes me wonder if he knows how exactly things should look, so perhaps he missed something.

Idemon, I'd suggest digging in again with your camera piece. The roller of the tensioner is right behind the cam chain tensioner and is facing the inside of the engine, so you'd need to do it from the top through the cylinder head (it's directly below the nylon sprocket, at the other end of the metal piece that sits below it).

For reference, this is what you are looking for. The cam chain should be sitting on the roller - the tension from cam chain tensioner is applied to the chain with this roller.
If it's messed up (in this case would be more like missing), the cylinder head must come off. It's much easier than swapping the engines.

So, I have checked everything.
1: I find it normal that there is a free play in the transmission gear and the chain of transmission? really not huge.

2: the roller look good, no deterioration or disintegration !!

3: the sprocket in white nylon up the roller for chamshaft chain! Is it normal that there is a free play left and right of 1/8 to 3/16 max?
all the rest seems A1 to me and my dad, I do not understand what happened.

Hmmm.... To all that read this after this update, I'd do the 1, 2, 3 steps I suggested originally in the recent post. At this stage, I'd take the 'gamble' and walk on the wild side. Two choices now then: run it or take it apart to pieces and become Sherlock Holmes!