No Spark

I am having an issue with my new to me 8N. when I got it I didn't realize it had a 6v positive ground system and I inadvertently connected a 12v battery with the positive terminal going to solenoid and negative terminal to ground. It Started right up ran for about 5 to 10 min and then died. I have removed the 12v battery replaced it with a new 6v battery connected positive to ground negative to the solenoid engine cranks but no spark. I thought I might have burnt out the ignition coil so Yesterday I replace the ignition coil with one from tractor supply and when ahead and put new spark plugs. However there still no spark. any help would be much apricated thanks

It's very possible that a new set of points would be the answer. It may also need a new condenser. Before that though, put a voltmeter on the coil primary. That should be about 6.3 volts when the switch is turned on. If so, try it at the points connection. If the points are open you should have the same voltage but it the points are closed the voltage should be near zero.

front or side distributor?
75 Tips

Side

Confirm that you have voltage to the coil. Battery voltage, points open. About half that if the points are closed.

Battery voltage means 12.65 volts on a 12v system and 6.35 volts on a 6 volt system. A light will not tell you that. Get a meter. The number 1 cause of no spark
or a weak spark is a weak battery.


Do you have battery voltage across the points when they are open? (with the points open, put one probe on one side of the points & the other probe on the
opposite side of the points) Verify the gap on the points at .025. Then, dress the points by running a piece of card stock or brown paper bag through them. New
points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam
lubricant. (I always spray my feeler gauge blade off w/ contact cleaner.) Make sure you have voltage across the points, as in past the insulator on the side of
the distributor. That is a very common failure point on sidemounts, along w/ the attached copper strip. It's hard to find a short there because it is usually
an intermittent . So 'wiggle' the insulator & the copper strip a bit when you are doing your checking. If you find the short there, the Master Parts catalog
lists everything you need on page 154. You can make the strip and you could also make the insulators as well. But, somethings are just easier & in the long run
cheaper to buy. Get the strip, 12209, screw 350032-S, 12233 bushing & 12234 insulator & just replace it all.


If you just replaced the rotor & lost spark, put the old one back in. Insure that the rotor fits firmly on the shaft & that the little clip is there. Make sure
the distributor cap is not cracked, doesnt have gouges in it from the rotor or brass shavings & doesn't have carbon tracks. Check continuity on the secondary
coil wire. Make sure it is firmly seated in both the cap & the coil. Next, remove the secondary coil wire from the center of the distributor cap, turn the key
on & crank the engine while holding the end of the wire 1/4 from a rust & paint free spot on the engine. You should see & hear a nice blue/white spark. If not,
you have a bad coil or condenser. Just put the old condenser back in to eliminate that as a possibility.

And do not buy a new part for the tractor until you can answer this question: how do I know the part on the tractor is defective?
75 Tips

(quoted from post at 07:34:45 08/25/21) I am having an issue with my new to me 8N. when I got it I didn't realize it had a 6v positive ground system and I inadvertently connected a 12v battery with the positive terminal going to solenoid and negative terminal to ground. It Started right up ran for about 5 to 10 min and then died. I have removed the 12v battery replaced it with a new 6v battery connected positive to ground negative to the solenoid engine cranks but no spark. I thought I might have burnt out the ignition coil so Yesterday I replace the ignition coil with one from tractor supply and when ahead and put new spark plugs. However there still no spark. any help would be much apricated thanks

Click to expand...

TSC 6 volt front mount coils are POS.

Last year I needed a coil for my 9N. TSC was only local with one in stock. I went to TSC and opened the box........whole top cover of coil was loose. I mean could lift top about 0.040" gap!!!

Went to NAPA and ordered an Echlin coil. No issues in the year it's been in the tractor.

Whoops read rest of thread, side mount dist........

This post was edited by Mad Farmer on 08/25/2021 at 12:21 pm.

I guess it's hit and miss,as I've had a TSC coil on my tractor for about 12 years with no trouble. The old one blew because someone
used a 12v battery with just the ballast resistor.