On Thu, 15 Apr 2004 14:56:57 GMT, "Roger Long"
om wrote:

Quite right. However our 172 N did not come with EGT as standard equipment.
The "lean to rough, enrich till smooth" I was taught in primary training
(and used for the first couple of years when our EGT didn't work) ends up
about 50 ROP on our engine if you do it quickly and without carb heat. It
was sloppy of me to call it a Lycoming recommendation.

I don't think I really learned how to lean until I had an EGT indicator.
and discovered how slowly the engine parameters change with changes in the
mixture control. At least in my fuel injected IO360.

And the lean to rough, enrich to smooth IS Lycoming's recommendation for
carbureted engines without EGT indicators or flowmeters. But they do say
to lean *slowly* and they also state it is for Economy cruise at 75% power
or less).

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




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