Notices
Gas Engines Questions or comments about gas engines can be posted here

Help reading plugs

Old 08-17-2009, 09:46 PM
  #1  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default Help reading plugs

Hey guys, I know this is a topic over and over, BUT.
I am running a DL-100 without any issues.
Turning a Mejzlik 27 X 10TH @ 6500 rpm.
I am at about 4 gallons in this engine and I want to take a look at the plugs.
I think the centers of the plugs look a tad on the rich side ( tan/brownish ).
I was concerned about the black wet looking build up on the outside edge of the plug.
I am running Pennzoil aircooled @ 40:1 and these are NGK CM-6 plugs.
The tuning might be good, but maybe to much oil?
The first two pictures are of the right side and the second two are of the left side.







Old 08-17-2009, 10:01 PM
  #2  
tschuy
Senior Member
My Feedback: (1)
 
Join Date: Jul 2003
Location: SeaTac - Angle Lake, WA
Posts: 1,057
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

Looks a little rich and too much oil... 40:1 is a bit much as evidence by the large amounts of black deposits. In short order you'll see some problems with the rings sealing. You are uing a good quality oil so thin it down to 50:1 and check the plug again after a few runs...<cite>

</cite> http://www.troybuiltmodels.com/ns/manuals/zdz_all.pdf


Old 08-17-2009, 10:32 PM
  #3  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I also just pulled the plugs out of my Yak.
DL-100, Mejzlik 27 X 10TH ( 6600 rpm ), NGK CM-6, eight gallons through it with Pennszoil aircooled @ 40:1
First two pictures are the right side, second two are the left side.
I am thinking the right side on this set looks a little lean, kind of white.











Old 08-18-2009, 05:12 PM
  #4  
flatspinjim
My Feedback: (3)
 
Join Date: Jun 2005
Location: ft lupton, CO
Posts: 895
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I just pulled the plugs on my DL just to see what they look like. It's got a little over 30 gallons through it. I'm running the same prop and oil, but right now I'm running 32/1 just because I'm breaking in another engine and don't want to carry 2 fuel jugs. Mine are a real nice light tan but with no oil around the plugs. I don't think you are running too much oil. I wouldn't worry about yours, just keep running it. I think these DL's take awhile to get really broke in.
I don't have a good camera to take pics with or I would post some of my plug.
Old 08-18-2009, 05:48 PM
  #5  
JoeAirPort
My Feedback: (41)
 
JoeAirPort's Avatar
 
Join Date: Aug 2003
Location: Milwaukee, WI
Posts: 10,259
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

They appear to have a light brown tint to them in the pic's and look fine to me.
Old 08-18-2009, 06:46 PM
  #6  
Jake Ruddy
Senior Member
My Feedback: (40)
 
Jake Ruddy's Avatar
 
Join Date: May 2005
Location: Bear, DE
Posts: 4,104
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

You can never run too much oil if you tune properly.

I think the first might be on the rich side a tad. 2nd looks fine. However it depends when you shut down the engine. If you had a long taxi back then you are not really getting a true reading. Best thing to do is to kill the engine right after you land. Then you can get a good reading on your high end which is mostly what you are using.
Old 08-18-2009, 07:25 PM
  #7  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

What octane fuel are you using? Judging by the heat line on the ground strap this engine needs more timing! That would help power output as well. The brand of gas you use and it's composition will greatly affect the coloration on the ceramic and electrodes of the plugs.
Old 08-18-2009, 07:34 PM
  #8  
Tired Old Man
Senior Member
My Feedback: (1)
 
Join Date: Feb 2002
Location: Valley Springs, CA
Posts: 18,602
Likes: 0
Received 3 Likes on 3 Posts
Default RE: Help reading plugs

In the last set of pics I saw what I believe to be an engine running lean. The early set of pics is an engine running wet and rich. A difference between sides is normal, but try to strike a balance between the two. The oil residue on the plug threads can be pretty much ignored.
Old 08-18-2009, 07:43 PM
  #9  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs


ORIGINAL: raflyer

What octane fuel are you using?
I am running regular unleaded ( 83 oactane, I think ).

ORIGINAL: raflyer

Judging by the heat line on the ground strap this engine needs more timing!
Which engine do you mean? 1st set of pictures is engine #1 and 2nd set of pictures is engine #2.
Old 08-18-2009, 07:58 PM
  #10  
w8ye
My Feedback: (16)
 
w8ye's Avatar
 
Join Date: Dec 2001
Location: Shelby, OH
Posts: 37,576
Received 7 Likes on 7 Posts
Default RE: Help reading plugs

Looks like it's the 2nd engine
Old 08-18-2009, 08:13 PM
  #11  
Tired Old Man
Senior Member
My Feedback: (1)
 
Join Date: Feb 2002
Location: Valley Springs, CA
Posts: 18,602
Likes: 0
Received 3 Likes on 3 Posts
Default RE: Help reading plugs

Pics in your post #3
Old 08-18-2009, 08:14 PM
  #12  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

Engine #1 is close, engine #2 is way off. Since we cant adjust the timing in the ign. module we have to play with octane and oil/fuel ratio. Higher octane fuels burn slower which changes the timing of the flame front/travel in the combustion chamber. I would run it on a leaner oil/fuel mix and look at that white insulator very closely and look for brown spots. That is the clue for slight detonation. You want the color change on the ground strap to be at the bend or slightly below it.
Old 08-18-2009, 08:18 PM
  #13  
crazyflyboy30
Member
 
Join Date: Jul 2009
Location: Beverlyhills, CA
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I saw it the same way.
Old 08-18-2009, 08:22 PM
  #14  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

Another trick you can do is bend the ground strap so it is only over the half of the electrode. If you look at eng#2 it looks to be that way while Eng #1 it is covering it. I also noticed that the gold plating is still on the electrode on Eng #1 which means it is way to rich but if the engine is new that is ok for now. Something to watch. Just remember, lean will kill the engine and rich will only lower the power and foul plugs. By kill the engine i mean destroy it so go slow and keep us updated. I tuned my FI street/drag cars by reading the plugs just as i have told you. Every engine and gas/oil mix combo is different so if you tune by reading your plugs you will find what works with YOUR combo. It worked for me, my Impala is still #1 and my Cobalt still #2 in the country after 3 years and i tuned it myself.
Old 08-18-2009, 08:26 PM
  #15  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

Can the timing be changed from T.D.C. @ 28 degrees to solve the problem or is there not enough movement with the hal senor?
Funny, that engine is stronger then the other engine and gets 100 more rpm.
Granted it has 4 more gallons run through it, but it is the stronger of the two.
Old 08-18-2009, 08:34 PM
  #16  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs


ORIGINAL: raflyer

Another trick you can do is bend the ground strap so it is only over the half of the electrode. If you look at eng#2 it looks to be that way while Eng #1 it is covering it.

Sorry if I am not understanding.
You are saying engine #1 is about right, but you want me to make engine #1's plugs look like engine #2's with the ground strap to be only over half of the electrodes ?
Old 08-18-2009, 08:38 PM
  #17  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I think i messed up the engines.. Need to number the plugs so i can better help you. The stronger engine is leaner and slightly retarded ign and the electrode is unshrouded nicely The wet plugs on the 1st eng? shows weak ign, to much oil, or junk gas even? Overall to cool in the combustion chamber. Believe or not though, retarded timing can cause excessive heat as well but i'm sure that is not the case here. As for changing the timing, that would involve moving the pick-up if not correct. To bad there isnt an adjustable pot in the module.
Old 08-18-2009, 08:45 PM
  #18  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs


ORIGINAL: 2robinhood


ORIGINAL: raflyer

Another trick you can do is bend the ground strap so it is only over the half of the electrode. If you look at eng#2 it looks to be that way while Eng #1 it is covering it.

Sorry if I am not understanding.
You are saying engine #1 is about right, but you want me to make engine #1's plugs look like engine #2's with the ground strap to be only over half of the electrodes ?
You have 8 pictures of plus and the first 4 look like 2 different engines. Sorry i confused myself and you.[&:]
Old 08-18-2009, 08:46 PM
  #19  
crazyflyboy30
Member
 
Join Date: Jul 2009
Location: Beverlyhills, CA
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I have a DLE-111 I can adjust the timing some and I did.
Old 08-18-2009, 08:51 PM
  #20  
raflyer
Member
My Feedback: (14)
 
Join Date: Jun 2002
Location: Greenfield, IN
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs


ORIGINAL: crazyflyboy30

I have a DLE-111 I can adjust the timing some and I did.
sweet! how did you do it? I dont have one yet but will be getting one soon.
Old 08-18-2009, 08:58 PM
  #21  
crazyflyboy30
Member
 
Join Date: Jul 2009
Location: Beverlyhills, CA
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

I did set my timing up some too run cooler.The pikup has a slot in it.
Old 08-18-2009, 09:00 PM
  #22  
mbinkley
 
Join Date: Jun 2004
Location: Harrisburg, PA
Posts: 203
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

Hello all,

Im in the a mantance mode on one of my planes that has a BME 115.
The engine has about 8 to 10 gallons of fuel 93 octane and the oil is pennsoil air cooled at 35 to 1.
This engine runs great and has a lot of power.

What to you guys think of the plug color?



Attached Thumbnails Click image for larger version

Name:	Db83845.jpg
Views:	16
Size:	41.2 KB
ID:	1258949   Click image for larger version

Name:	Xs59178.jpg
Views:	23
Size:	42.9 KB
ID:	1258950  
Old 08-18-2009, 09:06 PM
  #23  
crazyflyboy30
Member
 
Join Date: Jul 2009
Location: Beverlyhills, CA
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs


ORIGINAL: raflyer


ORIGINAL: crazyflyboy30

I have a DLE-111 I can adjust the timing some and I did.
sweet! how did you do it? I dont have one yet but will be getting one soon.
Onthe DLE-111 the pickup has a slot you move it some and I did a little.I will go back set to the best power.
Old 08-18-2009, 09:12 PM
  #24  
2robinhood
Senior Member
Thread Starter
 
2robinhood's Avatar
 
Join Date: Aug 2006
Location: Egg Harbor City, NJ
Posts: 760
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

OK, pictures are edited with what engine number and what side of the engine.
Old 08-18-2009, 09:13 PM
  #25  
crazyflyboy30
Member
 
Join Date: Jul 2009
Location: Beverlyhills, CA
Posts: 59
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Help reading plugs

What thrust can you out of that BME ?

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.