Hi Remzi.,
a lot of dutch do not speak dutch
your valve cover gasket can be out of place.,
you must open the valve cover and check it.,
it is a rubber cover, you should be able to use it again,and again.,
there are some sharp bends in this rubber gasket,
there you have to apply some liquid gasket for a better closing,
and be aware of the fact ,that you tighten the valve cover bolts with 20NM or approx 2Kgm.,
it is important not to overthigten your valve cover bolts!
i think your machine dying at full throttle is not a synchronisation problem, but more a mixture problem, not enough air of not enough gas., or just to warm ., but i am not sure on this, maybe other clubmembers know more
looked at your movie., i have never seen the bosporus, so have seen it now.,