Help Reading Spark Plug

[Poboy kartman]

2 things to remember. These are air cooled and need to run rich to run cooler which means more power. Also it's summer time so this is the richest the engine is gonna be for the whole year. I can tell you the plug that was in the barstool for 2 years and I've never had an issue with was closer to black than the usual tuned goldish color. And it's always ran perfect. Easy to start never cut out. Never missed the rpms once.

EXCUSE ME????? C'MON MAN!!!!! What is this ? Sadie Hawkins day?

It's gonna run the RICHEST.....in the hottest DRIEST part of the year?

That is beyond ridiculous!

Perhaps you meant NEEDS to run the richest....but....unless TUNED that way....it will indeed run the LEANEST!

 

[Denny]

Me I would go up 1 heat range and see how it does. (no pinging or melty looking stuff) I always believed run the hottest plug possible. Yes, Joe is right Doug. Hotter the air and the more humid it is = less dense air. Cooler and less humid = denser air, which = more power. My El Camino would drop 2 tenths of a second in Mid October from what it ran in mid July.

Denny

 

[chancer]

So Bob you need to go buy a psychrometer.

 

[bob58o]

If only anybody had an exhaust header with O2 sensor bung. LOL

I appreciate all the help.

I can get some more pics.

HOW IT BEHAVES....

Starts easy with choke on with the throttle cracked open.
Can turn the choke off right away.
Seems to let me start driving right away, (I can give it throttle without letting the engine warm up and it doesn't die - about 80 degrees today)
If I punch it from Idle and hold it, it will stall and die.
If I ease into WOT from Idle, there is a little (sputter or stumble or bog or hesitation or something).
With the hotter AR3911, that "bog thing" seemed better.
It didn't completely go away, but got better.
Once I get passed that (sputter stumble or bog or hesitation) it runs fine.
It seems like I can run at WOT all day with no problems.

Max RPMs and 1/4 mile times will be next.
You know I like numbers! It will be good for me to feel the kart with my butt, check the speed and rpm with gauges, and also look at the plugs with my eyes.

I just wanted to put this out there to see what I could learn. I liked the poll too.
More pics and testing to come.

Thanks again!
Bob

---------- Post added at 03:41 AM ---------- Previous post was at 03:18 AM ----------

PV = nRT
https://en.wikipedia.org/wiki/Ideal_gas_law

Pressure * Volume = Number of particles * constant * temperature

If pressure and volume stay constant (say 1 atm and 1 cubic foot) and temperature goes up....
The number of O2 particles has to go down.

Since the air is not in a closed system, as temp goes up... Pressure goes down. Same CFM will move less O2.

Less O2 with same jetting, means it will be rich.




http://www.onallcylinders.com/2013/...er-nature-how-to-tune-for-weather-conditions/
One of the keys to tuning for weather is the carburetor setup, jetting in particular. Here’s an example: when the thermometer rises, the density of the air decreases. That effectively decreases the available oxygen to feed the engine. Carburetor jetting should be reduced to compensate and prevent an over-rich air/fuel mixture


http://www.southbayriders.com/forums/threads/132589/
A bike tuned in summer will be lean in winter. The denser air has more O2 (but the CFM is the same). More O2 with same jetting will be lean.

---------- Post added at 03:46 AM ---------- Previous post was at 03:45 AM ----------

EXCUSE ME????? C'MON MAN!!!!! What is this ? Sadie Hawkins day?

It's gonna run the RICHEST.....in the hottest DRIEST part of the year?

That is beyond ridiculous!

Perhaps you meant NEEDS to run the richest....but....unless TUNED that way....it will indeed run the LEANEST!

I disagree.

Can I have this dance?

 

[Poboy kartman]

Wow!

This is why this forum is great.....open ears and open minds can learn much.

Trust me...it makes me want to look into this more....but I'm willing to admit I must be wrong.

 

[Joe-405]

I know some serious drag radial tuners. Like best friends from one of the fastest in the u.s.

It's a nitrous car on a 8.5" radial and runs 135+mph in the 1/8 mile. That's why I know that about tuning. If it can be done he can tune it. Mine might just be the fastest bolt on clone here really quick. His skills and my bike is gonna be alot quicker than usual !

 

[Flyinhillbilly]

Bob, with the adjustments I described what you are doing is increasing the vacum on the low speed circuit which in turn make it pull fuel earlier and harder. That's why you'll need to take some pilot jet out. What I think is happening is you have a signal problem band aided with too rich of a mixture. With the stronger signal the fuel will be emulsified better, and the velocity will be higher meaning better fuel shear at the transition slot, which means the fuel will be atomized better, meaning less chance of the fuel falling out of suspension. You may have to go up a tiny bit on the main to make up for the smaller pilot. Just give the engine what it wants is my rule, they never ask for too much if you know the language. Send me your header an I'll tig an O2 bung in it if you want me to, but I'm confident we can nail it down via plug readings.

 

[bob58o]

Bob, with the adjustments I described what you are doing is increasing the vacum on the low speed circuit which in turn make it pull fuel earlier and harder. That's why you'll need to take some pilot jet out. What I think is happening is you have a signal problem band aided with too rich of a mixture. With the stronger signal the fuel will be emulsified better, and the velocity will be higher meaning better fuel shear at the transition slot, which means the fuel will be atomized better, meaning less chance of the fuel falling out of suspension. You may have to go up a tiny bit on the main to make up for the smaller pilot. Just give the engine what it wants is my rule, they never ask for too much if you know the language. Send me your header an I'll tig an O2 bung in it if you want me to, but I'm confident we can nail it down via plug readings.

I was kidding about the header.

Not sure if you were following that thread at all. It was mostly a debate on tuning with o2 sensors vs plug reading.


I'm going to ride it for a bit today and see what I can learn.

I'm going to try to get the main get right first - based off timed runs.

What my baby wants, my baby gets!
Then I will work on the idle and transition.

For now, this is idle jet where the engine will die when fuel screw is turned in too far and seems to stumble when backed out more than 3 turns.

This is the fun stuff for me!!!! Thanks.

I love to adjust and GAB, so I think, with the backing of the forum, I will be able to get this as close as possible.

 

[ezcome-ezgo]

When the equilibrium is achieved, there will be a moment of silence.

 

[Flyinhillbilly]

I was kidding about the header.

Not sure if you were following that thread at all. It was mostly a debate on tuning with o2 sensors vs plug reading.


I'm going to ride it for a bit today and see what I can learn.

I'm going to try to get the main get right first - based off timed runs.

What my baby wants, my baby gets!
Then I will work on the idle and transition.

For now, this is idle jet where the engine will die when fuel screw is turned in too far and seems to stumble when backed out more than 3 turns.

This is the fun stuff for me!!!! Thanks.

I love to adjust and GAB, so I think, with the backing of the forum, I will be able to get this as close as possible.

Roger that, I've said what I have to say about it, I'm here to help if you need me. Fwiw, I tune turbo and nitrous cars off an O2 sensor and plug readings. On a N/A engine they'll live way out of tune, this stuff will turn a $10,000 (parts and machine work) race engine into a block that has 8 ashtrays where the pistons used to be before you can get your foot out of it if you get outside of about a 2.5 point AFR window. The stuff I generally tune is high stakes, and mistakes are expensive. This is one of the cars I tune and drive.

 

[Flyinhillbilly]

Before I ripped it apart to paint it.

 

[Flyinhillbilly]

My personal race car.

(Edit) not trying to brag or show off, just some reference material, or a resume if you will.

 

[Joe-405]

Here's the car I help with. He's really good tuner also...............

 

[chancer]

My personal race car.

(Edit) not trying to brag or show off, just some reference material, or a resume if you will.

Is that a G body?

 

[Flyinhillbilly]

Yes, 83 Grand Prix

 

[bob58o]

So the smoke ring at the bottom should indicate WOT mix, right?

I've looked at enough pics to see what that should look like.
It looks like I am close to just a bit lean. Since it will lean out in the cold Chicago winters and I'd rather be safe than sorry, I'd like a litter darker/thicker smoke ring at the base. Sounds right????




My $10 Hour Meter Tach is not working. I'll have to cut wires and solder a new battery I think.
I'll try to program the bicycle speedo again.

If I can manage to NOT break anything else, I am going to try this next..

AR3911 (same type plug as in the pics)
NO MUFFLER (Will lean out both jets a bit)
0.043" Main Jet (More Jet to make up for the muffler)
0.026" Idle Jet (Same jet size - hopefully leaned out by NO Muffler)

Going to make 3 WOT Runs and kill it on the last one.

Compared to the last reading, I expect less coloring on the tip and a similar sized smoke ring near the base of the insulator.

I think this will be close. Lets see how I do??????? I'll sacrifice another plug to the Petrol gods if need be?

https://www.youtube.com/watch?v=wWf3uzxOdKI

---------- Post added at 02:18 PM ---------- Previous post was at 01:54 PM ----------

For some reason I always loved Buick Grand Nationals since I was kid. I never knew anything about cars and still don't. I think I like how plain they look. Maybe when I'm ready to move on from go karts and mini bikes I'll buy a Turbo Buick Something??? LOL

GN?
T-Type?

I guess GNX would be out of my price range? LOL

7-8 seconds sounds like a good goal!
https://www.youtube.com/watch?v=NFrt1fp5NMQ

 

[bob58o]

Ok Round Two

No muffler (had muffler in previous pics)
0.043" main jet (bigger than previous pics)
0.02"6 Idle get (same)
AR3911 plug (same)

See I knew this muffler is restrictive.

This seemed to make better power at lower RPM. Gets to 3k quicker.

And I don't think I noticed a bog???
Hmmm??? I should have paid better attention???
Maybe it is gone with this set up????

How does this one look?
Mixture ring looks smaller, even with bigger main jet. And lighter in color. Leaner cause no muffler?

Looks like I can see a color change on the ground strap. <~Looks perfect? Might not be the correct line I'm seeing? Do you see an Annealing line?

Let's hear it fellas!
Thanks in Advance!
Bob

 

[bob58o]

Two

 

[bob58o]

Three

 

[bob58o]

Four