OS 32F carburetor drum spring

In spite of careful checking in fuel pressure line especially the one way valve and fuel filter constructive screw tightening with O shape rubber ring, OS 32F motor with YS fuel injection regulator system does not run stable at high speed, how come? Deeper consideration about this inconvenience led me some conclusion that the tension spring in the carburetor drum construction that plays the part of keeping the drum position laterally for the secondary fuel needle closing point and preventing inconvenient lateral sliding movement caused by the pressure oscillation in 2 cycle motor crank case produced beneath the piston.
A tiny coil spring is designed to keep the throttle valve drum in an adequate position to measure the amount of fuel firmly at any speed, so the tension strength of it is decided at some very suitable value after researches and developing by the factory. Any change would not permitted into a weaker strengthened one by an user based on some happening idea, reducing rotating resistance just like I did this time. Beginner and layman would realize that how much efforts had been done by the engineers after this kind of stupid experiment. Remembering the past, 35 years ago, I had an experience about carburetor drum oscillation phenomena on OS7D carb while idling operation. equipped in OS61VF motor. I should remember about this fact before I did the similar manners on OS 32F motor.