electronic ignition

[handy2]

1950




1950 Farmall C with positive ground electronic ignition. Worked perfectly until now. Will not even fire now.
Pulled distributer. Found a tablespoon of brown dust inside. ?? Did the dust come from wear on the magnetic ring that fits on the dist. shaft? Anyone else had this problem?

 

[used red MN]

Handy welcome to YT! My guess would be the rust came from the centrifugal advance mechanism behind the plate the points originally fastened to and likely you electronic pickup is fastened to. With the rotor in place you should be able to turn it in the clockwise direction with light pressure against the advance springs and it should return back to the original position smoothly as you relax. We are talking a 10 to 20 degrees of movement roughly. In the link click on ..Quick view.. on section 051. Clicking on the bold print there will take you into the diagram and descriptions, in this case I found that the quick view is a clearer diagram. I will not guarantee this is the distributor you have because there are a couple options but this is the most common one. The plate is part 12 and the advance is made up of parts 13 - 17 that mount on the distributor shaft 18. Pull that plate out and report what you see.
Edit: I meant to add as Steve said the rust is did not likely cause the electronic ignition to quit. I did not read all of what Steve said but it could be possible rust buildup on the magnetic pickup may have contributed to the tractor not starting. Then hopefully the other ignition did not get left on for a time without the engine running. This I understand can burn out so me of the modules that theses electronic conversions use. Sorry for the late night response that focused on the rust issue and not the real problem.
CNHI Farmall C distributor diagram


This post was edited by used red MN on 01/18/2022 at 05:10 am.

 

[handy2]

Red MN Correct diagnosis. Rust is from advancement mechanism. One spring missing, the other broken. It's a wonder it worked at all. Tractor always started well with old point sys. and especially with electronic conversion. Ordered new springs. Bought the C in 1957.

Thank you for the info, Lloyd MN Handy2

 

[Steve@Advance]

Good chance the rust is not what stopped the ignition from firing. A bad centrifugal advance will have a negative effect on performance, but not stop the spark.

Before taking the distributor apart, which will need to be done to properly clean and lube the centrifugal advance, check the shaft for side play. Some play is acceptable, but the pick up coil must not be able to touch the magnet ring. If it has been hitting, or is damaged, that is possibly why it has quit working.

But, the most common killer of electronic conversion kits is having the wrong coil or coil/resistor combination. The coil or coil/resistor combination needs to have about 3 ohms resistance across the primary terminals. Having too low resistance, as in a 6v coil on a 12v system will overheat the coil and overload the ignition module, eventually burning it out.

If there is a part number on the coil, research the number, see what the ohm rating is. You can't go by what the counter person sold you, it may have been reboxed, and good chance they don't have a clue about selecting the correct coil.