2robinhood

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.

tschuy

My Feedback: (1)

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

2robinhood

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.

flatspinjim

My Feedback: (3)

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.

JoeAirPort

My Feedback: (41)

They appear to have a light brown tint to them in the pic's and look fine to me.

Jake Ruddy

My Feedback: (40)

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.

raflyer

My Feedback: (14)

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.

Tired Old Man

My Feedback: (1)

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.

2robinhood

I am running regular unleaded ( 83 oactane, I think ).

Which engine do you mean? 1st set of pictures is engine #1 and 2nd set of pictures is engine #2.

w8ye

My Feedback: (16)

Looks like it's the 2nd engine

Tired Old Man

My Feedback: (1)

Pics in your post #3

raflyer

My Feedback: (14)

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.

crazyflyboy30

I saw it the same way.

raflyer

My Feedback: (14)

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.

2robinhood

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.

2robinhood

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 ?

raflyer

My Feedback: (14)

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.

raflyer

My Feedback: (14)

You have 8 pictures of plus and the first 4 look like 2 different engines. Sorry i confused myself and you.[&:]

crazyflyboy30

I have a DLE-111 I can adjust the timing some and I did.

raflyer

My Feedback: (14)

sweet! how did you do it? I dont have one yet but will be getting one soon.

crazyflyboy30

I did set my timing up some too run cooler.The pikup has a slot in it.

mbinkley

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?

crazyflyboy30

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.

2robinhood

OK, pictures are edited with what engine number and what side of the engine.

crazyflyboy30

What thrust can you out of that BME ?