The regulator on the Y-S is "Timed" by the crankshaft as well as being pulsed by the positive-negative pressure pulses inside the engine. This makes the regulator resposive to the engine speed. Therefore, it is a engine speed biased regulator.

The Cline and Iron Bay regulators are Demand regulators. They will not let any fuel through them unless there is a slight suction on the fuel line that goes to the needle valve.

The Cline's operating mechanism is pure Walbro carb regulator stuff from a weed eater engine.

The Iron Bay regulator uses a diaphragm to open a Shraeder valve like is in the valve stem of your car tire.

Enjoy,

Jim