What have leaning procedures got to do with anything?! You wouldn't be leaning as per the POH (in order to get best power/economy etc)... you're just leaning to a level where the power drops sufficiently. Would make for some interesting pops, bangs and the like, but would get the job done.
A single engine aircrafts throttle system is normally designed so that it fails to fully open
Does it? I've never heard of this, so how does it work? Are you suggesting that, in carbureted engines, there is a set position to which the throttle valve will go? Or are you saying that they never fully open? I'm not trying to be smart, just after some clarification, as I never knew about such things. What about on fuel-injected engines?
In all the PA28 POH's I've seen, it says to refer to the engine manufacturer's handbook for leaning procedures.
Thanks