Plug fouled

[Denny]

Well, having to do a bunch of cross country flying moving grandchildren
around, 20 hours over two weeks, means I had to put in 100LL at
whatever backwater airport I happened to be at, instead of the cheap
nasty mogas I usually burn... Of course, starting up on a remote
airstrip mean't finding a fouled plug from that leaded crap they call
avgas... No tools with me because I needed every pound of gross to
move overstuffed suitcases and five bodies... No mechanic within miles
and no reasonable way to find one... Luckily I was alone at that
point... After two attempts to burn the plug free failed, I sat there
and thought it through... Two engines... 8 cylinders... 15 working
plugs... And a light load... I opted to move the plane first and fix it
later... The take off was uneventful and the plug actually cleared
about 5 minutes later...

Burning mogas for years means I have basically forgotten what it's like
to have a fouled plug and so I sit there on the ramp quivering like a
student pilot with his first failed runup... The reminder was not
enjoyable... I'm going to order a new set of plugs as these have 500
hours and my mechanic has been grumbling... I'm toying with the idea of
fine wire plugs, but they are 3 times the cost of massive electrodes...
Gotta make a decision... Jeez I hate that....

denny

[RST Engineering]

Every now and again Aircraft Spark Plug Service (Van Nuys CA) has a set of
used fine wires for sale at a quarter of the cost of new ones.

Jim


"Denny" > wrote in message
ups.com...

I'm toying with the idea of
> fine wire plugs, but they are 3 times the cost of massive electrodes...
> Gotta make a decision... Jeez I hate that....
>
> denny
>

[[email protected]]

Denny > wrote:
: Burning mogas for years means I have basically forgotten what it's like
: to have a fouled plug and so I sit there on the ramp quivering like a
: student pilot with his first failed runup... The reminder was not
: enjoyable... I'm going to order a new set of plugs as these have 500
: hours and my mechanic has been grumbling... I'm toying with the idea of
: fine wire plugs, but they are 3 times the cost of massive electrodes...
: Gotta make a decision... Jeez I hate that....

To my mind, fine-wire plugs have to run pretty hot to keep from fouling, and
that means they have small, hot, pointy parts to them when running. I opted not to go
for them on my 180hp Lycoming I run mogas in for fear of preignition. If you run a
low-compression engine, it's probably not any cause for concern.

Just food for though, though...

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Jim Burns]

We've put about 30 hours on our plane since it's annual at the end of July
at which time we noted our plugs were pretty bad and most of the electrodes
were no longer very round, so we knew it soon would be time for new plugs.
Shortly after, our crop dusting friends called with a deal on new iridium
plugs, 1/2 price... $32 each. I've got them in the left engine but have
been waiting for an excuse to put them in the right engine. Now I've got
it, a re occurring fouled plug on the right engine. Like yours, it cleans
up in flight, but re-fouls occasionally on the ground, even with very
aggressive leaning. So, this weekend the right engine plugs will get
changed.

Jim

[Nathan Young]

On 1 Sep 2005 10:36:37 -0700, "Denny" > wrote:

>Well, having to do a bunch of cross country flying moving grandchildren
>around, 20 hours over two weeks, means I had to put in 100LL at
>whatever backwater airport I happened to be at, instead of the cheap
>nasty mogas I usually burn... Of course, starting up on a remote
>airstrip mean't finding a fouled plug from that leaded crap they call
>avgas...

Do you lean aggessively on the ground? The O-360-A4A in my Cherokee
fouls plugs if I place the mixture anywhere near (or higher) the
middle of travel. I have found that leaning to the point of engine
stumbling and then enriching a fraction eliminates fouled plug issues
- even on long taxis.

Nathan

[Robert M. Gary]

My Mooney will foul up really quick, but there are ways to prevent
it...

1) When taxiing on the ground, if adding throttle causes an increase in
RPMs, you are not leaning enough (increasing power on the ground should
be a two fisted task)
2) Full rich should be labeled "Emergency use only and sea level
initial climb out". The only time I ever push the mixture all the way
to the top is during the first 2,000 feet of take off from a sea level
airport.
3) Decend and land with the mixture leaned a lot. For go around, learn
to enrichen as you increase throttle
4) Buy a good engine monitor to ensure proper leaning in flight.

You really don't want extra fuel in those cylinders.
-Robert

[Robert M. Gary]

That's a good idea up to say 5,000 feet. After that you're just too
rich IMHO. In fact, when I had the Debonair I couldn't get over 8,000
at full rich. The Cont engine just didn't put out power above that
altitude with the mix rich.

-Robert

[Roger]

On 1 Sep 2005 15:29:33 -0700, "Robert M. Gary" >
wrote:

>My Mooney will foul up really quick, but there are ways to prevent
>it...
>
>1) When taxiing on the ground, if adding throttle causes an increase in
>RPMs, you are not leaning enough (increasing power on the ground should
>be a two fisted task)
>2) Full rich should be labeled "Emergency use only and sea level
>initial climb out". The only time I ever push the mixture all the way
>to the top is during the first 2,000 feet of take off from a sea level
>airport.
>3) Decend and land with the mixture leaned a lot. For go around, learn
>to enrichen as you increase throttle
>4) Buy a good engine monitor to ensure proper leaning in flight.
>
>You really don't want extra fuel in those cylinders.

I do in mine. I use it for cooling.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>-Robert

[Peter R.]

"Robert M. Gary" > wrote:

> That's a good idea up to say 5,000 feet. After that you're just too
> rich IMHO. In fact, when I had the Debonair I couldn't get over 8,000
> at full rich. The Cont engine just didn't put out power above that
> altitude with the mix rich.

And in case it isn't obvious to some, you are referring to a normally
aspirated engine. I fly a turbo-normalized V35 with a Continental IO-520
engine.

Not only do I have to keep the mixture full rich on climb out, I then have
to engage the low fuel pump setting from 5k to 10k, followed by the high
fuel pump setting from 10k on up (assuming the cruise altitude is in the
teens up to the very low twenties). If this is not done properly, the
cylinders and turbo inlet temperature really start to really heat up.

--
Peter
























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[Robert M. Gary]

Yes, non turbo only