YS system

The main reason to introduce YS fuel pressurized and regulatory system is the stable operation while the maneuver pattern and the unchanging fuel mixture especially on a late acting. Pressurized fuel supply consistent fuel mixture even when the plain rising up or coming down. So, a fine tuning on the main needle valve relying on a intuition is not required if the best setting at the taking off moment is established. From the beginning to the end of the patterns, stable, monotonous operating condition is proved, whatever quicker pattern might be drawn in the sky by the pilot.
In spite of these truth and fact, it's very seldom to come across with YS motors including 2 cycle ones recently, less more, I've never seen the independent YS system invited on the another motors except YS manufacturing.
Contrarily am I fond of this, setting that on OS 25 LA and OS 32 F have I some good operating conditions for both of them, remember here, the carburetor of 25 LA is exchanged with 25 FSR's one because of fuel squeezing mechanism.
YS regulator does not have enough capability to control the fuel amount at the lowest speed, so the only that position it is controlled by the squeezing mechanism. The key to establish the regulator operation is to adjust the angular position it to make the transition from the lowest to middle rotation with smoothness.
Once these adjustment is well done, the good operation described above would be proved so far as any dust like fiber should not be come into the fuel line.
Remember here, any 2 cycle motors would do, because the primary crank case pressure is the same, the amount of combustion displacement has nothing to do with the system. Even 180 motor or 049 would do.
The system mentioned above resembles with the relation between Bf 109 and Spitfire while the WW2, the former had the fuel injection system and the latter did ordinary natural aspirator carburetor, no argument is necessary to talk about the superiority between them.