Burning out a Magneto Drop

Having to clear an occasional fouled plug is much different than doing
it on a regular basis. If it's a regular thing, I'd find out what the
problem is. If it's once in a great while, I wouldn't worry a bit.

Used to have fouled plugs in my TriPacer when I first bought it. I was
flying in New Mexico where we flew at 9 to 10 thousand feet MSL and
always leaned. I was going full rich when beginning my descent and at
the next startup it'd be rough. Found that if I richened the mixture
gradually as I decended, it never happened.
--
Gene Seibel
Hangar 131 - http://pad39a.com/gene/plane.html
Because I fly, I envy no one.



"O. Sami Saydjari" wrote in message ...
I just received a booklet from TCM called "Tips on Engine Care" (a very
good book...available from TCM's website...http://www.tcmlink.com/). On
page 12 it says "Never but never attempt to "burn out" a magneto drop
with ground run-up. This 'time-honored' procedure succeeds only at the
expense of the engine's mechanical health."

Well, I was taught this time-honored way. What the book does not say is
what you are supposed to do when you get roughness in one magento. Ideas?

-Sami
N2057M, Piper Turbo Arrow III

"C J Campbell" wrote in message
...

" jls" wrote in message
You just
completed a descent with the mixture full rich and the engine idling --
lots
of cooling and plenty of opportunity for spark plug buildup.

A good reason to to enrichen the mixture on descent and landing. I always
go as lean as I can.


I suspect that
the detonation and premature ignition that result from your
recommendations
are even harder on an engine than occasionally clearing a spark plug.

No doubt!

Leaning an engine takes a little finesse. It shouldn't be done on the
ground unless you're in Denver or on a high-altitude ramp.

Woah! Don't spread this idea around! No amount of leaning can hurt your
engine at the low power that is usable on the ground. Most engines we fly
were designed for a different fuel and will foul if not leaned on the
ground. It isn't just the sparkplugs. The lead is building up on the valve
guides making them stick and putting strain on the valve train.

You want to lean on the ground so the engine will die if you try to run at
RPM above 1300 - 1500. That way you can't takeoff in a leaned condition
where you could hurt the engine at full power.

Leaning aggressively on the ground will minimize the plug fouling that
requires clearing mags.

--
Roger Long

"Roger Long" om wrote in
message news
Leaning an engine takes a little finesse. It shouldn't be done on the
ground unless you're in Denver or on a high-altitude ramp.

Woah! Don't spread this idea around! No amount of leaning can hurt your
engine at the low power that is usable on the ground. Most engines we fly
were designed for a different fuel and will foul if not leaned on the
ground. It isn't just the sparkplugs. The lead is building up on the
valve
guides making them stick and putting strain on the valve train.

You want to lean on the ground so the engine will die if you try to run at
RPM above 1300 - 1500. That way you can't takeoff in a leaned condition
where you could hurt the engine at full power.

Leaning aggressively on the ground will minimize the plug fouling that
requires clearing mags.

--
Roger Long

You are correct and if you had read along further in the thread's early
messages you would see that I clarified this statement, which was related to
clearing an engine by revving it up and leaning by pulling the mixture
control on the ground.