8N Ford coils

pat32rf · Dec 14, 2009

Looked at a buddy's 8N Ford tonight. Ran fine last week when he parked it. No spark now.
This fellow bought the tractor last summer but is the original shade tree mechanic. No meters, lotsa crescent wrenches and pliers, yet he is able to get any small engine running.

The tractor has been converted at some point to 12 volt, but I don't know if the coil is 6v original or 12v. We do get 13volt to the terminal on the top of the square coil/distributor assembly but I show NO continuity thru the primary side of the coil when I remove it. He has bought new points, rotor, distributor cap and condenser. He didn't want to buy a new $150 coil until he was sure. I don't want to see him burn out the new coil.
Should there be a ballast resister some where between the key and the coil or should it get full voltage when running? The new coil he is ordering is supposted to be 12 volt.
Is it possible to replace the points without removing the rad and grill? (we have 20" of snow and the beast is under a tarp)

wvpolekat · Dec 14, 2009

My 2N was converted to 12v and has a ballast resistor inline with the primary side of the coil. I assume that it has a 6v coil, but have never looked. I can't imagine the primary side of a 6v coil lasting long at 12v. If there is no resistor, either it was a 6v coil living on borrowed time or a 12v coil that does not require a ballast resistor.

RickB · Dec 15, 2009

pat32rf said:
Looked at a buddy's 8N Ford tonight. Ran fine last week when he parked it. No spark now.
This fellow bought the tractor last summer but is the original shade tree mechanic. No meters, lotsa crescent wrenches and pliers, yet he is able to get any small engine running.

The tractor has been converted at some point to 12 volt, but I don't know if the coil is 6v original or 12v. We do get 13volt to the terminal on the top of the square coil/distributor assembly but I show NO continuity thru the primary side of the coil when I remove it. He has bought new points, rotor, distributor cap and condenser. He didn't want to buy a new $150 coil until he was sure. I don't want to see him burn out the new coil.
Should there be a ballast resister some where between the key and the coil or should it get full voltage when running? The new coil he is ordering is supposted to be 12 volt.
Is it possible to replace the points without removing the rad and grill? (we have 20" of snow and the beast is under a tarp)

First off, an OEM coil for a front mount 8N distributer should cost no more than $65 USD, and aftermarket coils are less. Secondly, even a stock 6V front mount ignition system has a ballast resistor and requires an input voltage to the coil of about 4VDC. If your buddy's tractor has been getting a steady diet of 12V to the coil and the primary coil windings are open, he may as well buy a coil, points & condenser. Aftermarket coils are available for 12V conversions, follow their directions concerning input voltage, or install the original ballast resistor and an additional resistor if an OEM style coil is used. Two 5/16" bolts fasten the distributor to the block, remove the entire distributor to service the points. The drive tang is offset, so timing is not necessary at installation.

Soundguy · Dec 15, 2009

Rick gave you 110% great info.

150$ coils? WOW! hit a TSC.. they are 35$.. can get oem '6v' style.. or the newer 2.5 ohm 12v coils. As rck said, the new coils still need ressitance inline.. so follow the directions on your coil, whichever you get.

soundguy

brandoro · Dec 15, 2009

I'll be no help to the OP but thought some of you might answer a question for me. What is the rated horsepower of an 8N? The people I worked for on their farm when I was in high school, many years ago now, had one that I spent a lot of hours on. Always liked that tractor, cut and raked a lot of hay, pulled a pretty good width of harrows for hours and hours. Handy yard tractor with a small FEL too.
Anyway, just curious what the rating was.

ToadHill · Dec 15, 2009

27 pto Hp.

pat32rf · Dec 15, 2009

Thanks Rick- I'll pass the info on to him. He tried the new coil today but still has no spark. He has the new points and condenser but thought that he had to remove the rad to see what he's doing when setting the points. When I got the 13v reading the tractor wasn't running (no load) so there might or might not be a resistor in there someplace.

brandoro · Dec 15, 2009

ToadHill said:
27 pto Hp.

thanks ToadHill, just idle curiousity. Interesting how close that is to the B3030 I have now. Quite different tractor otherwise.

Soundguy · Dec 15, 2009

pat32rf said:
Thanks Rick- I'll pass the info on to him. He tried the new coil today but still has no spark. He has the new points and condenser but thought that he had to remove the rad to see what he's doing when setting the points. When I got the 13v reading the tractor wasn't running (no load) so there might or might not be a resistor in there someplace.

you pull 2 bolts and remove the dizzy.. not the rad.

13v sounds like an open circuit reading.

you can have a hundred resistors in line, and if the circuit is open 9 points open) there is no current flow, and thus no voltage drop. simple high school electronics at work here.

check the points gap.. should be .015 for a front mount.. plug gaps are .025 I like al437 plugs.. though al216 work as well as champh10 and h12, and ALC7 wich the local dealer will likely sell you.

soundguy

pat32rf · Dec 22, 2009

Turns out that when he bought the tractor last summer the points were really bad, but it started fine. It didn't see much (if any) use all fall, then he moved. It saw a longer running time in loading and unloading than it had since he bought it. Then it quit.
I checked the coil and found it had an open primary so he bought a new one ($100 plus $15tax) ordered from a local car shop. He also did the points and it started right up. It ran for about five minutes and quit. He tells me that the new coil got too hot to touch. (I think its fried).
He cannot find ANY ballast resistors in the wiring. I think that maybe the old points were burnt to the point that it wasn't passing enough current to burn the first coil until he let it run to warm up and recharge the battery after unloading it. New points compounded the problem.
We have since found replacement coils can be ordered at $50 (TSC and elsewhere) but the counterman tells him they come in 6 and 12 volt.( With a 12V he won't need another resistor, according to the kid on the counter) I am having trouble explaining to him that the crab coils are 6v, some of the tincan coils are 12. Either way he needs ballast resistors.
The minus 25degreeC weather doesn't help.....plus the fact that the tractor is 25 miles away...