A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Owning
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Color of spark plugs



 
 
Thread Tools Display Modes
  #1  
Old February 29th 04, 11:50 PM
john smith
external usenet poster
 
Posts: n/a
Default Color of spark plugs

We just did the annual on our 1945 Aeronca Champ.
Took the plugs out to do the compression test.
On inspecting them, noted that they were black, sootie.
The AI said that is normal for autogas in a Champ.

Honeck always says his plugs are clean when he runs autogas.
Is this the difference beween having a low compression, low horsepower,
no-mixture control engine and having a high compression, high
horsepower, mixture controlled engine?

  #2  
Old March 1st 04, 03:13 AM
G.R. Patterson III
external usenet poster
 
Posts: n/a
Default



john smith wrote:

Is this the difference beween having a low compression, low horsepower,
no-mixture control engine and having a high compression, high
horsepower, mixture controlled engine?


Sooty plugs indicate either a too-rich mixture or oil burning. I would say it's
the result of having no mixture control in this case.

George Patterson
A diplomat is a person who can tell you to go to hell in such a way that
you look forward to the trip.
  #3  
Old March 1st 04, 07:15 AM
john smith
external usenet poster
 
Posts: n/a
Default

G.R. Patterson III wrote:

john smith wrote:

Is this the difference beween having a low compression, low horsepower,
no-mixture control engine and having a high compression, high
horsepower, mixture controlled engine?



Sooty plugs indicate either a too-rich mixture or oil burning. I would say it's
the result of having no mixture control in this case.


I think it does run rich on the ground, but in cruise at 2150 rpm, I
only burn 3.5 per hour.

  #4  
Old March 1st 04, 02:16 PM
jls
external usenet poster
 
Posts: n/a
Default


"john smith" wrote in message
...
We just did the annual on our 1945 Aeronca Champ.
Took the plugs out to do the compression test.
On inspecting them, noted that they were black, sootie.
The AI said that is normal for autogas in a Champ.

Honeck always says his plugs are clean when he runs autogas.
Is this the difference beween having a low compression, low horsepower,
no-mixture control engine and having a high compression, high
horsepower, mixture controlled engine?

Some of those old Continental A-65 engines have mixture control, most don't.
I fly one that does but the plugs still get dirty. I use a little 100LL
occasionally to help the valves and seats. Try an additive to keep them
from fouling and clear your engine by gently revving it up for a couple of
seconds on the ground and on final. (BTW, I just read in the O-300
Continental manual where it says to "gun" your engine on final to clear it.)
A Marvel-Schebler carburetor has a better mixture control than a Stromberg,
the carb hanging from most A-65's. And most of the Strombergs have been
safety-wired to full rich.


  #5  
Old March 1st 04, 02:24 PM
john smith
external usenet poster
 
Posts: n/a
Default

jls wrote:
"john smith" wrote in message
...

We just did the annual on our 1945 Aeronca Champ.
Took the plugs out to do the compression test.
On inspecting them, noted that they were black, sootie.
The AI said that is normal for autogas in a Champ.

Honeck always says his plugs are clean when he runs autogas.
Is this the difference beween having a low compression, low horsepower,
no-mixture control engine and having a high compression, high
horsepower, mixture controlled engine?


Some of those old Continental A-65 engines have mixture control, most don't.
I fly one that does but the plugs still get dirty. I use a little 100LL
occasionally to help the valves and seats. Try an additive to keep them
from fouling and clear your engine by gently revving it up for a couple of
seconds on the ground and on final. (BTW, I just read in the O-300
Continental manual where it says to "gun" your engine on final to clear it.)
A Marvel-Schebler carburetor has a better mixture control than a Stromberg,
the carb hanging from most A-65's. And most of the Strombergs have been
safety-wired to full rich.


We have the Stromberg without the mixture control.
The Bendix carbs with the mixture control are hard to find (lots of
people looking for them). The AI said they don't really do that much for
you on the ground.

OT... He did say that he, too, noticed better performance from 100LL
than from autofuel.He also said that he prefers to fly his Champ with a
mixture of autofuel and 100LL.

  #6  
Old March 2nd 04, 04:08 AM
external usenet poster
 
Posts: n/a
Default

On Mon, 01 Mar 2004 13:24:25 GMT, john smith wrote:

snip

We have the Stromberg without the mixture control.
The Bendix carbs with the mixture control are hard to find (lots of
people looking for them). The AI said they don't really do that much for
you on the ground.


The "mixture control" is nothing more than an adjustable bowl vent.
Only flown behind a couple of them, didn't notice any big difference
between the knob being in or out.

I would check the primer pump for leaks, and verify that the seat
height is set correctly. Not sure how much difference it makes, but
with these carbs I've always dummied up the carb install (placing it
at the same height in relation to the fuel in the airplane) to shim
the seat.

I'm assuming that you've already had the Delrin needle/float weight
installed.

Always wanted to drive one with the MS carb on it, never had the
opportunity.

OT... He did say that he, too, noticed better performance from 100LL
than from autofuel.He also said that he prefers to fly his Champ with a
mixture of autofuel and 100LL.


The one I learned to fly in was operated on a mixture of 80, 100LL,
and TCP. Was kinda hard to tell what "color" the plugs were, it tended
to swill engine oil.

TC




 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: 182 Cowl Plugs, Pitot Cover, Sunscreens Robert Bullock Aviation Marketplace 0 May 25th 04 05:05 PM
Bougies blindées BG à vendre/BG spark plugs for sale stef General Aviation 0 May 14th 04 04:57 PM
RFQ Igniter plugs Juan*Jimenez Aviation Marketplace 0 April 23rd 04 11:13 PM
2nd update on Review of Plasma II Ignition System MikeremlaP Home Built 8 July 22nd 03 01:37 AM
spark plug question Bill T. Owning 0 July 3rd 03 07:08 PM


All times are GMT +1. The time now is 03:05 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.