1952 8N No spark

Original 6 v system - I was getting intermmitent or no spark at plugs and from coil wire. I changed the rotor and coil. It ran fine for about 10 minutes and died. fuel looks fine, starter fluid would not start tractor. now I have no spark from coil. I took the cap off, turned key on, turned engine over and there is no spark (arc) across points. thank you for the help.

jump power to the coil primary.. IE.. bypass key switch.. recheck and post back.

points gapped at .025?

soundguy

I will try that, unfortunately I won't be able to till later (after work). FYI, I have a multimeter and checked the voltage at the terminal block (two wires where the ignition switch goes to) and I get 6+ when key is on. Of course I may be losing it from there to coil. what kind of reading (volts) should I be getting at coil? Question: I installed the coil with the + going to the distributor; Is this correct? Do I run a jumper wire to + side? Yes points are gapped .025.

No spark, so you replaced the coil. Troubleshooting the problem would have your tractor running w/o a new coil. There are two schools of thought when it comes to getting a non-running tractor to start. One way is to just start replacing every part you can get to until it starts or you run out of money. The other way is to take a step-by-step approach to solving the problem, working from most likely to least likely. The trick to fixing these tractors (or trouble shooting any piece of equipment) is to be systematic about it. You need to isolate the problem step by step and work from most likely to least likely. You have solved half the problem by determining it is a spark problem. That doesn’t mean you need to replace all of the electrical parts on the tractor!

Get your meter out. The ignition circuit goes from the battery to the terminal block then to the switch then to the coil then by the primary (little) wire on the coil to the points. Trace the circuit. W/ the points open, you should have battery voltage everywhere in the circuit.

Do you have battery voltage across the points when they are open? 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 guage 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 & doesn't have carbon tracks. Check continuity on the secondary coil wire. Make sure it is firmly seated in both the cap & the coil. In fact, replace it temporarily w/ a plug wire. 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.



Post back w/ results; I'll be interested in what the problem was.
50 Tips

"I installed the coil with the + going to the distributor; Is this correct? "

Yep. Tip # 33
50 Tips

a multi meter alone is a bad source to check for ignition power. a test lamp should be used in combination. input imeadance in a vom is so high that even a switch with dirty contacts will show voltage, even if the connection is so bad that it won't flow current to run a test lamp or coil.

soundguy

I appreciate all the information. I agree, I need to troubleshoot instead of buy parts till I run out of money.

I read somewhere about the voltage across the points (when open) and tried that last night after it stopped running and got a reading. I will check for a short at the points as you recommended. the plug and coil wires are new. I did not change the points and condensor so I can't put the OLD one back in. Could it be a condensor?

maybe worth noting, after buying the tractor, I had the carb rebuilt checked the plug gaps, point gap and timing. the tractor fired right up, but I did notice a miss and I never saw a nice white/blue spark, always a weak orange spark. I ran the tractor and it stopped. after cooling down, it started right back up. this had happened a few times, till it would not start at all. that's when I went and bought the coil. but here I am again, ran for about 10 minutes and now I have no spark.

again thank you

(quoted from post at 01:58:33 06/02/11) I appreciate all the information. I agree, I need to troubleshoot instead of buy parts till I run out of money.

I read somewhere about the voltage across the points (when open) and tried that last night after it stopped running and got a reading. I will check for a short at the points as you recommended. the plug and coil wires are new. I did not change the points and condensor so I can't put the OLD one back in. Could it be a condensor?

maybe worth noting, after buying the tractor, I had the carb rebuilt checked the plug gaps, point gap and timing. the tractor fired right up, but I did notice a miss and I never saw a nice white/blue spark, always a weak orange spark. I ran the tractor and it stopped. after cooling down, it started right back up. this had happened a few times, till it would not start at all. that's when I went and bought the coil. but here I am again, ran for about 10 minutes and now I have no spark.

again thank you

Click to expand...

On my side mount 8N, to check for spark I like to set the points so that they are closed, after settin the .025" gap, then hold the high tension wire from the coil near a good ground and then open the points with my finger. If the points are making contactd and you have voltage to the points yo will get a spark. Points get dirty and coroded and need to be cleaned or replaced.

still need help - somebody posted this recommendation for checking distributor continuity. I think it's wrong if you use a testlight with the key on

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.
2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.
3. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!
4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

If this is right, should I check with a tester that has it's own power source (i.e. ohmmeter)?

is there a procedure to follow for testing these things. in other words, first test this, then this, etc, etc....?

(quoted from post at 09:37:48 06/02/11) still need help - somebody posted this recommendation for checking distributor continuity. I think it's wrong if you use a testlight with the key on

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.
2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.
3. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!
4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

If this is right, should I check with a tester that has it's own power source (i.e. ohmmeter)?

is there a procedure to follow for testing these things. in other words, first test this, then this, etc, etc....?

Click to expand...

othing wrong with his procedure........but it isn't written for your tractor. Different machine. So, yes, it is wrong for 'your' tractor.

thank you. that's why my handle is 8N Rook. the rook is for rookie.