Run up for plug clearing

Roger Long wrote:
#&*(^%$#!)+=- Microsoft.

With the budgets that world domination provides, you would think
someone would have figured out that putting the Send button under the
Reply button would lead to inadvertent blank replies.

With Windows 98, you could move the buttons around so that didn't
happen when you accidentally double clicked. Eliminating that option
seems to have been one of those "Innovations that users demand."

Right click on the toolbar, hit "customize" and move the buttons anywhere
you want.

#&*(^%$#!)+=- Microsoft.

With the budgets that world domination provides, you would think someone
would have figured out that putting the Send button under the Reply button
would lead to inadvertent blank replies.

With Windows 98, you could move the buttons around so that didn't happen
when you accidentally double clicked. Eliminating that option seems to have
been one of those "Innovations that users demand."

--

Roger Long



"Roger Long" wrote in message
. ..


--

Roger Long



"Larry Dighera" wrote in message
...
On Sat, 09 Oct 2004 10:54:44 GMT, "Roger Long"
wrote in ::

It worked but running the engine full power (near sea level) while leaned
for best power and peak EGT with minimum airflow for the minute it took
seems pretty abusive to me.

That's what I was taught. Often it only takes 10 - 15 seconds to
clear/burn the carbon deposit without the necessity of leaning. I
don't see anything abusive or abnormal about this procedure, as the
engine sees full throttle on each takeoff.

In article ,
Larry Dighera wrote:


That's what I was taught. Often it only takes 10 - 15 seconds to
clear/burn the carbon deposit without the necessity of leaning. I
don't see anything abusive or abnormal about this procedure, as the
engine sees full throttle on each takeoff.

A difference between a runup and the takeoff roll is the cooling air
flowing thru the cowling when moving. There is very little airflow when
stationary, even with high power settings. I'm not saying you shouldn't
do a high power runup, but you should be cautious and aware of the
possibity of heat problems.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

--

Roger Long



"Larry Dighera" wrote in message
...
On Sat, 09 Oct 2004 10:54:44 GMT, "Roger Long"
wrote in ::

It worked but running the engine full power (near sea level) while leaned
for best power and peak EGT with minimum airflow for the minute it took
seems pretty abusive to me.

That's what I was taught. Often it only takes 10 - 15 seconds to
clear/burn the carbon deposit without the necessity of leaning. I
don't see anything abusive or abnormal about this procedure, as the
engine sees full throttle on each takeoff.

I've only had 2 incidents of plug fouling. The first, ironically, right
after I had asked my stage 3 check instructor if I should lean during taxi.
He said no. A few minutes later, I learned to clear my first plug. I
remember using runup power and just leaning aggressively. No CHT or EGTs
available. That was in a C150.

I had a real bad mag drop a couple of weeks ago in my Tripacer. My brakes
were a little on the weak side and, being that it's a hand brake, I couldn't
go higher than 1800 without starting to roll. I ran it up (1800) and leaned
until It was barely running smoothly (probably lean of peak). I did this
twice for about 30 seconds each. There were planes waiting behind me and the
second time didn't get it, so I pulled off the taxiway and repeated the
procedure for a full minute nad that got it. Had that not worked, I wasn't
going flying that day.

I don't think there's a real limit. If I had toe brakes, I might have tried
a higher power setting. Even now, in my TP, my brakes are back to full
strength, I would have tried as much power as the brakes would hold.


Just my $.02-and worth every bit of it. :-)

mike regish

"Roger Long" wrote in message
...
I can't remember where I "learned" it but I always thought 1800 RPM was the
limit for ground running leaned to clear plugs. I had a really bad one
yesterday with 250 RPM drop. I taxied back to the shop and they said to
try full throttle before pulling the plugs.

It worked but running the engine full power (near sea level) while leaned
for best power and peak EGT with minimum airflow for the minute it took
seems pretty abusive to me. Maybe you can get away with it because the
CHT's have not yet risen to max.

Any thoughts? What were you taught?

--

Roger Long

On Sat, 09 Oct 2004 10:54:44 GMT, "Roger Long"
wrote in ::

It worked but running the engine full power (near sea level) while leaned
for best power and peak EGT with minimum airflow for the minute it took
seems pretty abusive to me.

That's what I was taught. Often it only takes 10 - 15 seconds to
clear/burn the carbon deposit without the necessity of leaning. I
don't see anything abusive or abnormal about this procedure, as the
engine sees full throttle on each takeoff.

The answer to questions such as this can be found in the POH from the
manufacturer who supposedly knows more than the average flight instructor or
public thought about what is right.

For the Cessna Model 152 Section 4 Normal Procedures under "Takeoff" "Power
Check" says
"It is important to check full-throttle engine operation early in the
takeoff run. Any sign of rough engine operation or sluggish engine
acceleration is good cause for discontinuing the takeoff. IF THIS OCCURS,
YOU ARE JUSTIFIED IN MAKING A THOROUGH FULL-THROTTLE STATIC RUNUP BEFORE
ANOTHER TAKEOFF IS ATTEMPTED. The engine should run smoothly and turn
approximately 2280 to 2380 RPM with carburetor heat off and mixture leaned
to maximum RPM."
(Emphasis added.)

You will not harm the engine therefore if you use 2000 RPM and lean to clean
the plugs.

I suggest if you are serious about this you discuss the matter with a
mechanic.

"Daniel L. Lieberman" wrote in message
...

The answer to questions such as this can be found in the POH from the
manufacturer who supposedly knows more than the average flight
instructor.

I just love posts like this one!!

A good flight instructor would know that the answer to this question is
not a general answer that works for all aircraft and would therefore not
deal with it on a newgroup forum or in person before checking it out for
engine manufacturer recommendations and POH remarks as the answer
relates to the SPECIFIC aircraft/engine combination involved with the
question.
Although your answer is correct, unless you are one of these "pilots" on
"piloting" who think CFI's are morons, I see no reason to assume that
the "average" flight instructor wouldn't be intelligent enough to do
this.
Dudley Henriques
International Fighter Pilots Fellowship
Flight Instructor/Aerobatics/Retired

Dudley,
You have made my point. There is a POH for every plane. A pilot should read
it when he has a question. He is supposed to always be learning. If he has
found an answer then he should verify what he has found with a CFI if he
feels it necessary.

The question did NOT contain the necessary information to find a specific
answer. What I quoted was quoted as an example of what can be found by
reading the POH.

The instructor obviously, if he is competent, which we must assume until
proven otherwise could answer the question - what does that teach the pilot?

The pilot has the ultimate responsibility for what he does. At some time he
must cut the apron strings and act like a PIC. That obviously requires
asking a more knowledgeable person if he cannot answer a question himself
with a little work.

Daniel

P.S. I believe that almost all CFIs are competent. The ultimate goal is to
generate a safe pilot who can fly himself.

"Daniel L. Lieberman" wrote in message
...
Dudley,
You have made my point. There is a POH for every plane. A pilot should
read it when he has a question.

Of course.


He is supposed to always be learning.

Basic flying 101.

If he has
found an answer then he should verify what he has found with a CFI if
he feels it necessary.

One way to handle it that's for sure. He could also check any and all
available sources of information as he should be doing; and this would
include any good CFI; the result should be a path leading directly to
the manufacturer's POH.
My point was simply that your statement as worded assumed that the
"average flight instructor" might not know enough to point the
questioner in the direction of the POH; an assumption I totally disagree
with.
I have no problem at all with your basic premise that checks the POH. In
fact that would be MY answer as well. Since I'm a flight instructor, and
would have done that, your added "assumption" to your comment about
CFI's not necessarily knowing enough to point a pilot to the POH I
thought might need a bit of "adjustment" so to speak. :-)

The question did NOT contain the necessary information to find a
specific answer.

Correct.

What I quoted was quoted as an example of what can be found by
reading the POH.

Also correct. Just don't assume that the "average flight instructor"
wouldn't know enough to point someone in the right direction.


The instructor obviously, if he is competent, which we must assume
until proven otherwise could answer the question - what does that
teach the pilot?

Don't assume anything in flying. It will kill you in short order! As for
"teaching the pilot". It isn't a CFI "game". If a pilot has a question,
you give him what you have and point him in the right direction to the
answer. In this case it's the POH. Any informative source can do that.
It's up to the pilot to make maximum use of all available sources and
sort out the good from the bad.
Again, my comment on your remark is directed only to your instructor
reference being not as reliable as the manufacturer's POH. BOTH should
be equally reliable in the context of this question; the POH for
supplying the needed data and the instructor for supplying the path to
the POH for obtaining that data.
It's no big deal, but I like to keep the air nice and clean when it
comes to statements about instructors.
Your basic point about the POH was correct. In my opinion, your added
reference about the "average instructor" I thought needed some
additional clarification which we have done I believe.
Dudley Henriques
International Fighter Pilots Fellowship
Flight Instructor/Aerobatics/Retired




The pilot has the ultimate responsibility for what he does. At some
time he must cut the apron strings and act like a PIC. That obviously
requires asking a more knowledgeable person if he cannot answer a
question himself with a little work.

Daniel

P.S. I believe that almost all CFIs are competent. The ultimate goal
is to generate a safe pilot who can fly himself.