8N electrical problems?

What was happening was that I would use it for 15 - 30 minutes and then it would start sputtering and stall shortly after. I would have to wait 2 - 4 hours before it would run normal again. Looking around this forum, the symptoms sounded like a bad ballast resister. Sure enough, mine was bad. When I put a new one on, I had similar problems. I also read in this forum that you can run without the resistor, just don't leave the key on when not running or you can damage the points. So I tried that once; the tractor started and idled for a few minutes and eventually stalled out. I really couldn't get it to start right since then with the resistor. Without the resistor it would start. What I just did today was put a 12 volt coil on to completely bypass the resistor and the tractor started up and ran great (for one pass around the yard). It stalled similar to before. The only difference this time seems to be that I can restart after a short period of time (10 minutes).

After I restarted it I decided to not rev it up too high so that the alternator would not kick in. I was thinking that maybe too much juice was being sent to the coil. After my one lap, it stalled again.

Any ideas?

Thanks,
Eric

it sounds like you are still overheating the coil. In a 12 volt system, the TOTAL resistance of the ignition coil and ballast resistor should be 3.0 ohms resistance, +/- 10%. Measure the resistance of the coil with an ohmmeter and also measure the resistance of the ballast resistor (if you're using one). Add them both together, it should be close to 3.0 ohms to work properly. If you don't add up to 3.0 +/- 10%(that's 2.7 to 3.3 ohms), then you have to either add a ballast or remove (replace with the correct ohm rated resistor). This should get you up and running with no problems....Don't operate your tractor in it's present state or you'll likely burn out the coil you have now also. The symptoms you describe sounds like you don't have enough resistance in your ignition circuit, and the coil is overheating, and when that happens, the tractor dies. Ignition coils are very dense, with the iron core and copper windings, and oil filled interior, it takes a long time for them to cool down.

Good luck,

Brian

Thanks Brian and Dell for all of the help!

Eric

The contacts get gunked up and heat up an suddenly "no runny". This typically takes about 15 minutes to heat up and 2 hours to cool down to restart. When you put the full 12 volts to your 6 volt ignition coil, you burned it out which is why you couldn't restart it. When you changed to a 12 volt coil, you still have your ignition key switch heating up and stopping the running BUT you have less relative voltage loss and the 12 volt coil puts out more sparkies sooner.

If you don't believe me, make up a jumper wire and jump across your ignition switch leads next time it stops, bet it fires right up without having to wait for the internal switch contacts to cool down.

Simple fix, replace your ignition switch..... ..Dell

Any more suggestions?

Thanks,
Eric

What is you confidence level in your 12 volt battery being up to charge? Batterys do have a "rebound" factor and with a good ignition system it could well be strong enuff to power you around a couple of times before the battery becomes discharged enuff that you don't make enuff sparkies to run good.

You mentioned something about disconnecting? the alternator.

Lean carb mixture of course will also cause spluttering, there is always the possibility of clogged fuel filters eventually not flowing as much gas as your engine needs eventually starving it to a stop. Check all 3 filters, including the one in the elbow of the carb. Take off your gas line at the carb, should flow freely, if it piddles your 2 filters up at the shut-off valve need checking.

One other possibility, water in the gas but your filters should stop that. I once had water that only effected when driving over ruff ground, kinda slopped over and filled the carb. I finally drained over 2 qts out. Still don't know how it got in.

Hope this helps, please keep us posted, we care..... ..Dell

The last time it sputtered out I didn't wasn't getting any spark at all. I took the coil off and and put 12 volts into it and, around 12 volts where coming out of it. I then looked at the points and noticed that they were pressed together and didn't move when cranking. They aren't "welded" together, i.e. I can easily separate them by hand.

Obviously, now I am having a points problem, but could they have been why it was sputtering out before?

Thanks,
Eric

Basically, when the points close, direct current flows thru the coil primary winding of the coil. Transformers (coil) don't like direct currents BUT thats how we transform 12 volts to 15,000 volts needed to jump the sparkplug gap and ignite the compressed fuel/air mixture in the cylinder head.

And the way we transform is to use the electromagnetic properties of the coil iron core and the direct current flowing thru the primary creates a great big magnetic field. It takes time to build this magnetic field, but once the points open, the magnetic field colaspes almost instantaniously. And when the magnetic field colaspes the magnetic lines of force cut thru the secondary (high voltage) winding very, very, very fast and transforms 12 volts to 15,000 volts to jump the sparkplug gap.

Ok, so now we introduce the effect of point gap. If the point gap is larger than specified, this means the time to build that magnetic field is not very long. And with a short time, the magnetic field is not very big. And with a small magnetic field, you don't get the 15,000 volts that the sparkplugs need. And consequently, the engine doesn't run well or not at all.

Now then, what happens if the point gap is too small? It means the magnetic field doesn't get time enuff to collaspe before it is being rebuilt. It takes the full collaspe of the magnetic field to generate the full 15,000 volts needed to make the sparkies work.

Now then what happens if the points never open? The magnetic field is built because the points are closed and conducting current thru the primary. BUT it is the collaspe of the the magnetic field that creates the sparkies. And since the points never open, the magnetic field never collaspes and you never get 15,000 volts to make the sparkies work.

So now that we understand the roll of the points in the ignition system, you should understand why the points need to open to the correct gap. Ignition points can and do "slip" and causes all kind of sparkie problems. Reset your point gap, secure the point screw tightly. However, check your point screw threads, they have been known to become worn or stripped.

Hope this helps, keep us posted, we care..... ..Dell