Fouled Plugs

[Ricaroo]

I put a new set of plugs in the cub (D16) Because the other set fouled on me. This is the third set this year. Could I have a coil problem and if so how do I check it or could it be a carb adjustment. The screw on the carb is apx 1 1/2 turns open. If I turn the screw on the carb in will that lean the mixture or make it richer?

Thanks
Rick

[cjpenny89]

how often do you run the cub? Do you work it hard? the d-16 is a cooler plug and is great if you really work the tractor. But if you don't use it much and just haul wagons and stuff like that then put in some d-21's

[John *.?-!.* cub owner]

First thing i'd do is go to a higher heat range plug. D21 is waht most people run for light duty such as weekly mowing, etc.

[George Willer]

Rick,

Next time use D-21 plugs. They are hotter and more likely to burn the stuff off them. Turning the idle screw in reduces the air and makes the mixture richer.

[Dale51]

I don't have the #'s handy but I have found the champions even the D21
foul faster than AC or Autolites this is not only cubs but a lot of other vehicles.
I have a 85 dodge with a slant 6 engine & it hates champions but will just pur on a set of AC's.

[superc_1]

I use AC Delco plugs. I've been told by alot of old timers thats there the best there is when it comes to plugs. I've never had a problem with them and I've owned 2- super C's, 2- A's, and now my cub.

[Eugene]

What is causing the plugs to foul? Usually a good indication of some sort of mechanical problem.

Excess fuel - adjust the carburator float level - needle valve and seat.

Oil - hotter plugs and just live with it. Worn engine - perhaps you can step up in engine oil weight - try straight 30 weight engine oil. Stuck rings - perhaps Sea Foam will loosen the rings.

Antifreeze/water - head gasket. Usually only one or two plugs fouling.

Just a couple of thoughts.

Eugene

[Jack]

superc_1 what is the number of the AC plugs you use?

[John *.?-!.* cub owner]

Champion D16 and D21 both cross to AC 87 or Autolite 386

[George Willer]

Chris Klossner's cross shows the following:

D-16 = A/C 85S or 86 and Autolite B9

D-21 = A/C 87 or Autolite B11

It's all Greek to me, I try to stay with Champions, usually D-21. They use good steel for the shells, good porcelain for the insulator and good steel for the center electrode... same as all other companies. After the proper heat range is selected, the rest can't be rocket science.

[RedNed]

It's all Greek to me, I try to stay with Champions

Correct me, doesn't AC stand for Albert Champion.One of them Champion brothers. Or is that just a urban legend.

[Dale51]

If you dought then try this.
Find a old spark plug tester & cleaner.
Put the air pressure to the plug of your choice & see at what pressure to spark stops the try the other brand.
You mite be suprised

[Eugene]

Correct me, doesn't AC stand for Albert Champion.One of them Champion brothers. Or is that just a urban legend.

Nope AC stands for Allis Chalmers. I used Champion D18Y plugs in a worn out Cub engine. Didn't foul.

Eugene

[George Willer]

If you dought then try this.
Find a old spark plug tester & cleaner.
Put the air pressure to the plug of your choice & see at what pressure to spark stops the try the other brand.
You mite be suprised

I got rid of my cleaner/tester, but the test function mostly was a sales gimick that depended on the squareness of the center electrode and the gap. Really, smoke and mirrors.

[WKPoor]

Well I'll add my 2 cents worth here also.
First off when someone says one brand preformed better than another its hard to quantify that statement. But just like a well tuned engine- you just know it by the way it sounds and feels. You don't really measure the performance , you just know especially if you've operated the equipment for a while. I'm so dialed in on my H I can tell a difference when I switch brands. Yesterday the Gravely oil fouled a plug so I put in a new Champ J8C. I could tell right off something didn't sound right and it had a miss at idle. Went and bought an Autolite and it purrs like it used to. Can't explain it, just know what I experienced.
I seem to have in the last couple off yrs settled on the Autolites because I like their smaller outer electrodes. I agree with George there shouldn't be a difference in brands if they perform according to design. But plugs are like oil. Everybody's going to have a preference even if there is no proof in superiority.