mikeeech, Buddsy: thank you for the inputs!
At first the cooling system had a clogged heating radiator, a fault gauge sender and a non working thermostat.
I also changed one of the fans because its electric engine burned.
Now both fans works fine. Two new thermostats were testet, normal and "hot climate". Heating core is clean. Little change.
Engine still runs on the "hot" side (fans activate too often, most of the time, also when riding at 80 km/h on open road...).
I agree with Buddsy: "hot climate" thermostat will make the engine run too cool when winter, with no cooling improvement in the summertime over the normal thermostat.
And now there is the leaking... I want to get a definitive solution!!
Thanks again,
Jorge E