does a twin engine lose its gyroscopic properties of inertia?

[jf1981]

Originally Posted by raaaid

two counterotating gyros as can be a planes lose their increased resistance to spin since theyre counter rotating

Most probably just the opposite, a single spinner induces a yaw during a stall, having hence more tendency to spin rather than preventing it doing so.

That can be seen in the sim, when you roll over 180° then pull back on the sticker hardly, the aircraft does not just half loop straight away, it also yaws.
If you violently pull in a straight and level flight, you will also notice that yaw coming in as soon as the pitch rapidly changes. I would assume that this comes from the spinner effect. This effect induces a spin. cr-spinners aircraft does'nt have such effect has and so would stall rather than spin under same circumstances.

That's something rather easy which you seem to make complex. The forces are held by the airframe with contra rotating spinners, the airplane forces are in equilibrum, that's why they designed such things, even a Spitfire in the 40's had such a duplex propeller.

There's no secret lying behind that if you try to understand with something more serious than a witch drawing, you'll probably understand why this is so.