On Thu, 15 Apr 2004 22:34:24 GMT, "Roger Long"
om wrote:

If you lean slowly in your 172N to rough, then slowly enrich until just
smooth -- where do you wind up with regard to EGT?



I'm going to try and trace my thought processes back here because I think a
lot of 4 banger, fixed pitch pilots are still flying the way I have at
various times.


I also don't think you can do it cookbook style. I suspect you have to go
through the fiddling stage, trying different amounts of carb heat and
learning the way the engine sounds and reacts at different points. After
that, it should be easier.

I'm still learning about it which is why I'm curious what kind of experience
other simple engine fliers have if they try it (as opposed to just
pontificating about it).

Interesting and educational story. It is clear that, in your engine,
following Lycoming's recommendations does result in running 50°F ROP. That
may not be what L intended, but that surely seems to be the result.

I, too, was never taught to properly lean. And I probably didn't really
learn to do it correctly until I'd owned my own airplane for five or ten
years (or maybe longer). There were a number of Mooniacs who were
recommending leaning to 50° rich for best power. In retrospect, although I
probably was aiming for that, I was likely a lot richer due to making the
adjustments too quickly.

But my "mature" Mooney would never show cruise CHT's much above 325°; and
my engine problems necessitating early O/H have not been related to
leaning.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)