This is the exact procedure we've used to set the mixture. The idle is 650
rpm and the increase when you move to cut-off is only about 25 rpm.

The problem is that it still seems too rich, especially in the pattern with
carb heat on.

"Ron Rosenfeld" wrote in message
...
On Wed, 31 Mar 2004 23:28:37 -0500, "Dave Gribble"
wrote:

Anyone have any experience like this?

No experience with the O320, but with the Lycoming O360's, the procedure
to
set proper mixture should be doable on the ground.

1. Start engine and warm up until CHT's and oil temps are normal.
2. Mag check -- if normal, proceed.
3. Set throttle set screw so idle is per airframe mfg recommendation.
4. Slowly move mixture control towards idle cut-off and observe rpm. An
increase of more than 50 RPM indicates the mixture is too rich. (An
immediate decrease, if not preceded by a momentary increase, indicates the
mixture is too lean).
5. When performing step 4, don't let the engine cut out.
6. Adjust the mixture control in the proper direction; run up to 2000 RPM
to "clear" the engine, and repeat the above as necessary. If the mixture
change has changed the idling RPM, that should be re-adjusted as needed.
7. If the setting does not remain stable, check the idle linkage for
looseness.


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