THE MOMENT OF TRUE.

Based on your statement that you heard a noise like the pistons hitting valves, I would still do a compression check to ensure that you have not bent valves.

Kawboy wrote:

Based on your statement that you heard a noise like the pistons hitting valves, I would still do a compression check to ensure that you have not bent valves.

I'll do that.
I'll ask a friend for a compression tester.
What would be the tolerance values ​​for correct operation?

From page #182 in the Service Manual. I would be happy if you found 130 PSI  (9.14 Kg/Cm2 )  with no more than 10% between cylinders. 

Be careful with a borrowed compression tester. I found out the hard way that compression testers have a special Schrader valve with a very light spring. Many people have replaced the Schrader Valve with one used for a tire and it will cause a compression tester to read as much as 40-50 psi lower than the correct reading. Schrader Valves for compression testers have a break out pressure of 5-8 psi meaning that it takes 5-8 psi to open the valve. Most tire Schrader valves need 20-30 psi to open the valve.

Compression testers are great for a quick check but if you find a problem, you really need a leak down tester to determine what is the problem. Leak down testers will tell you if you have a bad valve ( and which one) , a bad set of piston rings, or bad head gasket.

Loosening the mounting screws on the tensioner as you described could have resulted in over tensioning the cam chain when you re-tightened them. 

biltonjim wrote:

Loosening the mounting screws on the tensioner as you described could have resulted in over tensioning the cam chain when you re-tightened them. 

Assembling the chain tensioner correctly, I realized that it moved back a few millimeters when moving the chain up and down by hand between the two axles, resulting in loss of tension.
The way I did the test, moving the tensioner back a couple of millimeters before tightening the screws, the chain did not come loose or lose tension again.
Anyway, this was as a test to check the correct operation of the motor, making sure that the chain is tensioned without losing its shape when rotating.
As I said in another post, I am waiting for a new tensioner with a different design than the original.

So since I have the endoscopic camera I have photographed the piston heads inside the cylinders.

The first photo is cylinder 1 and so on until 6.