Re: using choke to kill engine?
I think we're "splitting hairs" here, it's simply an unnecessary procedure without any perceivable benefit yet with a slight chance of the minor detrimental effects mentioned above. I'm not sure why the minuscule "pressure on the needle and seat" is something to be concerned about as it's a normal function of the carburetor. The OP was asking about routine engine shutdown, save for long term/seasonal storage draining the fuel from the carburetor is simply unneeded, should it leak, it needs to be repaired and/or the fuel supply shut off while parked.
While not critical for our application, enriching the fuel/air mix via choke/enrichment circuit to initiate engine shutdown is SOP for ultralights and other small prop aircraft for the reasons previously stated.
BTW, the correct procedure for the winterization/long term storage of an outboard when disabling the fuel supply is to introduce a "fogging oil" while the engine is still running to prevent corrosion as well as lubricate a two stroke during this lean condition.
Last edited by BarelyAWake; 10-08-2011 at 04:04 AM.