What exactly is a fouled plug?

[Caryc]

8N side mount. My tractor was getting hard to start. When I did get it started, it would bog down when on a slight incline with a box blade full of dirt.

I put a new set of plugs in it and it still bogged down under a load though. After I put the new plugs in, I used a couple cable ties to bundle the wires up to keep them away from any heat.

When I tried the tractor, it acted like it was running on three cylinders so I checked out the wires and number three wire was completely out of the distributor socket. I replaced that and one other wire with a new one and it started up fine but still bogged down under a load.

I figured number three plug may have been fouled from the tractor running on three cylinders so I replaced all the plugs again.

Result...tractor runs fine now. So could that number three plug have gotten fouled from running on three cylinders and what exactly is a fouled plug? What does it look like?

Now the only thing I have to address is a new throttle plate and rod. Mine is slipping now. I imagine it will be like everything else and welded up with rust from over the years. I also have the Davis loader frame in the way so it will be no picnic to get the old crap out.

 

[Nick167]

If it was running on 3 cylinders an the cylinder that wasn't firing had the could plug it could be the unburnt gas on there it would be wet enough to retard the spark hold the plug tip in a propane torch for a few seconds should burn all the unburnt gas off there

 

[TheOldHokie]

(quoted from post at 21:31:33 12/05/14) 8N side mount. My tractor was getting hard to start. When I did get it started, it would bog down when on a slight incline with a box blade full of dirt.

I put a new set of plugs in it and it still bogged down under a load though. After I put the new plugs in, I used a couple cable ties to bundle the wires up to keep them away from any heat.

When I tried the tractor, it acted like it was running on three cylinders so I checked out the wires and number three wire was completely out of the distributor socket. I replaced that and one other wire with a new one and it started up fine but still bogged down under a load.

I figured number three plug may have been fouled from the tractor running on three cylinders so I replaced all the plugs again.

Result...tractor runs fine now. So could that number three plug have gotten fouled from running on three cylinders and what exactly is a fouled plug? What does it look like?

Now the only thing I have to address is a new throttle plate and rod. Mine is slipping now. I imagine it will be like everything else and welded up with rust from over the years. I also have the Davis loader frame in the way so it will be no picnic to get the old crap out.

A fouled plug is one that has a layer of foreign material built up on it that interferes with the formation of the spark. Fouling can be minor to massive. This one is pretty bad and I doubt you will fix it with a torch ;-)

TOH

 

[Hobo,NC]

The spark followed the path of least resistance... What ever fouled it became a conductor and the spark went directly to ground... No spark the plug got wet with un-burnt fuel are oil are what ever contamination that was in the combustion chamber that became a conductor...

 

[Dell (WA)]

Cary.......there are many types of fouled plugs ...but... the result is the same, they don't sparkle the mixture inside the cylinder. Great picture of oil fouled plug BTW.

Howsomevers, yer description of boggin' sounds to me as MAL-ADJUSTED carbie. Turn yer down-pointing MAIN-JET to 2-turns and LEAVITT!!! Adjust yer side-pointing IDLE-MIX for FASTEST idle, NOT smoothest idle. Understand the difference??? Then adjust the behind the carb idle speed for a SLOW 400-500 rpms. Then re-adjust yer idle-mix for FASTEST idle again. Do that idle-mix adjust at least 3-times. I've gotten my eazy starting 6-volt 52-8N down to 350-rpms, but generally adjust for about 450-rpms on proof-meter.

One of the FIRST things a neubie tractor driver does when he starts haffin performance issues is grab them handy-dandy carb tweek'ums. WRONG thing to doo. Changing sparkies was probably the best thing you couldda done. We recommend AutoLite 437's gapped 0.025". Modern "no-lead" gas is fulla additives that will FOUL yer sparkies.

Speakin' of wires, DO NOT USE modern carbon fiber (string) sparkie wires, use old fashioned COPPER core wires, cut to length. .......HTH, Dell

 

[Caryc]

(quoted from post at 03:27:41 12/06/14) Cary.......there are many types of fouled plugs ...but... the result is the same, they don't sparkle the mixture inside the cylinder. Great picture of oil fouled plug BTW.

Howsomevers, yer description of boggin' sounds to me as MAL-ADJUSTED carbie. Turn yer down-pointing MAIN-JET to 2-turns and LEAVITT!!! Adjust yer side-pointing IDLE-MIX for FASTEST idle, NOT smoothest idle. Understand the difference??? Then adjust the behind the carb idle speed for a SLOW 400-500 rpms. Then re-adjust yer idle-mix for FASTEST idle again. Do that idle-mix adjust at least 3-times. I've gotten my eazy starting 6-volt 52-8N down to 350-rpms, but generally adjust for about 450-rpms on proof-meter.

One of the FIRST things a neubie tractor driver does when he starts haffin performance issues is grab them handy-dandy carb tweek'ums. WRONG thing to doo. Changing sparkies was probably the best thing you couldda done. We recommend AutoLite 437's gapped 0.025". Modern "no-lead" gas is fulla additives that will FOUL yer sparkies.

Speakin' of wires, DO NOT USE modern carbon fiber (string) sparkie wires, use old fashioned COPPER core wires, cut to length. .......HTH, Dell

Thanks Dell, but the problem is fixed. It was running on three cylinders so it was not the carb. It's running on one of Garys rebuilt carbs which I haven't had to touch yet. When it's running on all cylinders, I don't even need the choke to start it.

I do use 437's and the ignition wire I use is from Napa. It is not copper but it is some kind of metal core.

 

[rustred]

a little tip... do not bundle and tie plug wires together. have you noticed how wires are neatly routed more so on vehicles. each wire is not to touch each other.
as for fouling you need to do a compression check. that tells the story.
to help prevent fouling on worn engines is to run them hot as in up to operating temp even if you have to cover the rad as required.

 

[Caryc]

(quoted from post at 10:50:46 12/06/14) a little tip... do not bundle and tie plug wires together. have you noticed how wires are neatly routed more so on vehicles. each wire is not to touch each other.
as for fouling you need to do a compression check. that tells the story.
to help prevent fouling on worn engines is to run them hot as in up to operating temp even if you have to cover the rad as required.

In those original tube type ignition wire routers on these tractors, tell me how the wires are kept from touching each other.

I live in California so my tractor always comes up to operating temp when I use it.

 

[rustred]

well that is kind of a not really correct thing that was engineered into the tractor.it is not common to have wires mounted that way. wire coating deteriorates and then if they re touching the spark will jump to the next wire. I remember on those old vehicles if you open the hood at night it looked like a lightening show as you could see the spark jumping all over the wires. and also consecutive firing orders were bad for that like the ford which ended in 7 and 8 cyl. firing after each other.
but anyhow check compression and that will give you the engines condition.

 

[Caryc]

(quoted from post at 16:55:30 12/06/14) well that is kind of a not really correct thing that was engineered into the tractor.it is not common to have wires mounted that way. wire coating deteriorates and then if they re touching the spark will jump to the next wire. I remember on those old vehicles if you open the hood at night it looked like a lightening show as you could see the spark jumping all over the wires. and also consecutive firing orders were bad for that like the ford which ended in 7 and 8 cyl. firing after each other.
but anyhow check compression and that will give you the engines condition.

Well, I don't know how many times I have to say it. There is no problem now. But thanks for the info.

My whole purpose for the thread was to ask what exactly a fouled plug was, not how to fix anything. But maybe all the advice given in this thread will help someone else.

 

[rustred]

well you asked, what exactly is a fouled plug. so then you should have known that replacing it does not fix the fouling problem. and you should have known that a compression check was the next step to see why it happened. so why did you ask? merry Christmas.

 

[Caryc]

(quoted from post at 22:59:21 12/06/14) well you asked, what exactly is a fouled plug. so then you should have known that replacing it does not fix the fouling problem. and you should have known that a compression check was the next step to see why it happened. so why did you ask? merry Christmas.

Ok, I see you evidently didn't read or understand my post. I asked about a fouled plug because the tractor was bogging down with a load on it.

While checking around, I found that one wire was actually pulled all the way out of the distributor so that cylinder was not firing at all.

Once I fixed the wiring problem it still didn't want to run right so I changed the plugs to new ones and it's running fine now so I figure that the plug was fouled from not firing.

Read the fourth and fifth paragraphs in my original post.

Get it? Do you understand now?

 

[pconnie]

i am surprised you didn't thank hobo and the old
hokie. they gave a concise explanation of what a
fouled plug is..thanks hobo and hokie

 

[Caryc]

(quoted from post at 10:21:38 12/07/14) i am surprised you didn't thank hobo and the old
hokie. they gave a concise explanation of what a
fouled plug is..thanks hobo and hokie

Why are people trying to make a bad guy out of me? Did you read this?

"But maybe all the advice given in this thread will help someone else."

Maybe I didn't exactly say it but I meant all the good advice given here. If you need a personal "THANK YOU" to make it official...Thank you hobo and hokie.

Are you happy now?

I depend on all the knowledge there is on this site. We all know who the very knowledgeable people are and I appreciate their advice.