# 6v coil cooked?



## bobaloo11 (2 mo ago)

I purchased a 9N recently from a guy who converted it to 12v. I asked the guy if he changed the ignition parts, he said "no". I got it running for a total of an hour or so, then it just stopped and it hasn't started since.
If the guy left the 6volt coil and ran it on 12 volts did it fry the coil? I know it's getting fuel but no spark. I hope it's the coil.
Any help would be appreciated 👍


----------



## Groo (Jan 17, 2020)

bobaloo11 said:


> I purchased a 9N recently from a guy who converted it to 12v. I asked the guy if he changed the ignition parts, he said "no". I got it running for a total of an hour or so, then it just stopped and it hasn't started since.
> If the guy left the 6volt coil and ran it on 12 volts did it fry the coil? I know it's getting fuel but no spark. I hope it's the coil.
> Any help would be appreciated 👍


I wouldn't jump right to the coil. I would look at stuff like points and condenser(?), cap and rotor first. I am seriously rusty on points ignition systems myself. Easy enough to do a resistance check on the coil.


----------



## dirtscratcher (3 mo ago)

A 6 volt coil needs an external resistor in series to drop the the 12 volts to 6 volts, or replace with a 12 volt coil which has the resistor built in. My experience when putting 12 volts through a 6 volt coil without the resistor is that you will continually burn up points. I'd start with the points, and get the resistor or change the coil. Your coil is probably ok.


----------



## bobaloo11 (2 mo ago)

If the ignition is on but motor isn't running, how fast can points fry if they were closed?


dirtscratcher said:


> A 6 volt coil needs an external resistor in series to drop the the 12 volts to 6 volts, or replace with a 12 volt coil which has the resistor built in. My experience when putting 12 volts through a 6 volt coil without the resistor is that you will continually burn up points. I'd start with the points, and get the resistor or change the coil. Your coil is probably ok.


Yeah, I'm gonna do points, and check cap rotor while I'm in it.


----------



## dirtscratcher (3 mo ago)

If it's not running, you'll just run the battery down. It's the high energy output of the coil when running that sparks and burns up the points when running.


----------



## dirtscratcher (3 mo ago)

dirtscratcher said:


> If it's not running, you'll just run the battery down. It's the high energy output of the coil when running that sparks and burns up the points when running.


I should have added that always change the condenser when changing the points, it's what protects the points during normal running by absorbing the current generated in the coil primary preventing it from arcing over the points. However running it without the resistor the condenser can't take the excess energy and can't protect the points, and may be damaged itself.


----------



## wolfang (2 mo ago)

dirtscratcher said:


> I should have added that always change the condenser when changing the points, it's what protects the points during normal running by absorbing the current generated in the coil primary preventing it from arcing over the points. However running it without the resistor the condenser can't take the excess energy and can't protect the points, and may be damaged itself.


----------



## wolfang (2 mo ago)

Yeah, you have to have an external resistor if you use the old 6-volt coil and distributor, and you need a toggle switch to cut off the 12 volts going to the external resistor when the tractor is not running, or you will still burn up the points. When you have this install (can buy this at most auto parts dealers) take a voltmeter and check for 12 volts going into the resistor and at the end going to the coil check for around 6 volts after cutting on your toggle switch power cutoff. If all this checks out, then you have only to deal with a bad coil or bad distributor cap or bad points or incorrect point gap (the thickness of a paper matchbox cover is close enough) and you set this with the distributor off the tractor on a front mounted distributor and it has a slot on back to gear up to the timing gear so you can't screw up here. On the oil fill side of the distributor is a screw that you loosen to set the timing (up Advances and down Retards) the timing and it doesn't move much either way. As I said before these old tractors require a lot of mechanical work and I do own one. Good Luck, you will need it! K


----------

