How did this distributor cap even work.

[Rick Remmert]

I had a 53' Super C valve cover leaking. While I had it off, I decided I might as well run the valves. I pulled the plugs out and took the distributor cap off so I knew what cylinder I was on. I just turned it over using the fan. This is what the inside of an 8 or 9-year-old distributor cap looks like. I can't believe this even ran. It has never missed a beat and always starts after barely turning over. I don't know why it didn't at least break the rotor. I hope someone on here can tell me why it is so corroded over. This tractor spends its time in an in-town garage. The weephole under the bottom clip was not plugged.

 

[old]

I had a 53' Super C valve cover leaking. While I had it off, I decided I might as well run the valves. I pulled the plugs out and took the distributor cap off so I knew what cylinder I was on. I just turned it over using the fan. This is what the inside of an 8 or 9-year-old distributor cap looks like. I can't believe this even ran. It has never missed a beat and always starts after barely turning over. I don't know why it didn't at least break the rotor. I hope someone on here can tell me why it is so corroded over. This tractor spends its time in an in-town garage. The weephole under the bottom clip was not plugged.

It is called high voltage and it will do some things you would not believe

 

[rustred]

that is normal for brass when it gets moist... it turns green. saw lots like that.

 

[Janicholson]

I had a 53' Super C valve cover leaking. While I had it off, I decided I might as well run the valves. I pulled the plugs out and took the distributor cap off so I knew what cylinder I was on. I just turned it over using the fan. This is what the inside of an 8 or 9-year-old distributor cap looks like. I can't believe this even ran. It has never missed a beat and always starts after barely turning over. I don't know why it didn't at least break the rotor. I hope someone on here can tell me why it is so corroded over. This tractor spends its time in an in-town garage. The weephole under the bottom clip was not plugged.

Looks normal to me. As rustred indicates, the Patina on the copper is common when exposed. Even more interesting it is not a real contact, but a jump to tower that is receptive of a spark. I would clean out the specs of dust in it, and put it back on with no issues or worry. Jim

 

[wore out]

Looks normal to me. As rustred indicates, the Patina on the copper is common when exposed. Even more interesting it is not a real contact, but a jump to tower that is receptive of a spark. I would clean out the specs of dust in it, and put it back on with no issues or worry. Jim

I agree with Jim, a little "corrosion" on the brass is "invisible" to high voltage.

Conductive deposits between the high-tension terminals is a far worse situation, bleeding off spark energy and/or causing firing of the wrong sparkplug.

 

[Rick Remmert]

Looks normal to me. As rustred indicates, the Patina on the copper is common when exposed. Even more interesting it is not a real contact, but a jump to tower that is receptive of a spark. I would clean out the specs of dust in it, and put it back on with no issues or worry. Jim

The thing that bothered me the most, was if you look at all 4 terminals, the rotor was making contact at the very edge of the terminal. It was so far off that it was wearing a groove in each terminal. That cap had to be way out of rotation to have that happen. There was no markings on the box as to where it was manufactured. I am going to replace everything in the distributer just to be on the safe side.

 

[BarnyardEngineering]

Yup, that lightning bolt will jump through any little pinhole in the insulation. A little corrosion is child's play.

The points are only conducting 12V, which is why a little corrosion kills spark.

 

[rustred]

The thing that bothered me the most, was if you look at all 4 terminals, the rotor was making contact at the very edge of the terminal. It was so far off that it was wearing a groove in each terminal. That cap had to be way out of rotation to have that happen. There was no markings on the box as to where it was manufactured. I am going to replace everything in the distributer just to be on the safe side.

that is normal also. the rotor contact does not contact the cap contacts. there is an air gap between them when the rotor is rotating. and it is not sending the spark through when both terminals are in alignment . that cap is in good condition , just needs the terminals cleaned. i notice it even has the firing order #'s on the inside. and it it hard to even get one with brass nowadays, as they are like aluminum terminals.

 

[wore out]

The thing that bothered me the most, was if you look at all 4 terminals, the rotor was making contact at the very edge of the terminal. It was so far off that it was wearing a groove in each terminal. That cap had to be way out of rotation to have that happen. There was no markings on the box as to where it was manufactured. I am going to replace everything in the distributer just to be on the safe side.

Varying the breaker point gap a little will affect where the spark from the rotor "lands" on the distributor cap terminals.

If the marks are on the trailing edge of the terminals DECREASING the point gap a little will make the spark "earlier" and it will land closer to the center of the cap terminals.

Just say'in!