TC said 'Odds are - the fuel shut off is electric upon which once the lever leaves the ON detent, the motor will activate and close the HP valve ASAP'. I have to question whether TC has ever seen a HU269? It's one of the most rudimentary helicopters out there, and it certainly doesn't have an electric fuel cock! It's a simple cable operated device (tap/faucet) via the instrument panel and yes, there could be varying degrees of off or on. So fuel flow could be adjusted by careful adjustment of the fuel shut off control. However, I suspect that being a piston engine, it would quickly mess up the mixture and stop the engine anyway. If it was a turbine, like the HU369, then, in theory at least, the rpm could be controlled with the fuel shut off valve. Not such a stupid question after all Nige.