Idling drifts

Automatic choke module angular position was re-adjusted just a bit precisely this morning as to be able to start motor with one action and continue warming up period of time with increased rotation sufficiently.

I found out some strange phenomena that the nose up parking makes the idle speed increase about 500rpm, how come?
Why the inclination with nose up figure increases the motor rotation?

The change of fuel pressure makes it?
The fuel tank would be rise up at higher position if parked with nose up figure. But remember here that the 34PICT3 carburetor had been so designed as not to be influenced by vehicles inclination, float chamber system. Then what makes the idle speed changes by the parking ground inclination?

Deeper inspections and consideration must be done to obtain clear answer for the strange phenomena.
Bon holidays are best opportunity for the upper purpose, it's convenient for me.
Anyway I'll do by myself, to myself and for myself, because no other external factor would not satisfy myself.

Of course the way to know the truth and the fact is not always so easy as to be paved so smooth for the frontier, I must go on the decided way and must keep the original direction, otherwise I would loose my own identity in future.