EDIT: Nellie's Firing Now!

[Stanton]

Still having trouble with my '47. She's a 6 volt, positive ground, magneto with external ignition coil and battery-start setup.

Found this from another thread (viewtopic.php?f=1&t=61588&p=505305&hilit=+simple+test#p505305):

Basicaly you have a standard battery operated ignition system. Some place along the line the coil in the magneto has been disconnected and an external coil added.

A simple check first. Remove the wire from the side of the magneto. Remove the wire from the center of the distributor/magneto cap and lay it next to the engine block so that you have a 1/4" gap between the end of the wire and the engine block. Turn on the ignition. Touch the wire removed from the side of the magneto to the magneto. Then remove. If there is a spark the problem is in the magneto points.

No spark. You need a test light or multimeter to check out the ignition system. With ignition switch on, starting at the wire from the side of the magneto - start checking for battery voltage at each junction/connection - tracing the wiring back to the battery. Once you find battery voltage - the problem will be the previous appliance or wire between the voltage and the previous junction/connection.

While trying to do this, I discovered two of the four spark plug wires (#1 and #3) with burned ends at the rotor cap; points inside of the cap also show evidence of burning. I tried the simple test above and got no spark.

Need some clarification:
1. The test above says to "Turn on the ignition." Does that mean only turn on the switch, or turn on the switch and engage the starter?
2. What's the purpose of placing the center wire 1/4" away from the block?
3. Also, if no spark, could it be due to the burnt out points under the rotor cap?
4. I have a multimeter. On the advice above, do I leave the black lead from the multimeter on the side post at the magneto and start using the red (positive) lead at each electrical connection until I see voltage?
5. Can I test the ignition coil while it's still connected to the tractor's wiring or do I need to remove the wiring to/from the coil?

Sorry for the length of this post. Electrical issues always seem to intimidate me. Any help is, as always, appreciated.

[Bigdog]

1. Just turn the switch on - do not engage the starter.
2. Placing the high voltage wire 1/4" from the frame provides a place to check for spark. A good working system will jump an arc 1/4"
3. Yes it can. If you have spark at the center wire on the coil but not at the plugs - the cap and rotor are usually the problem (assuming the timing has not been changed)
4. When checking for voltage readings lead placement depends on the polarity of your system. For a positive ground system connect the red lead to ground (not the distributor lug) and take readings with the black lead. If your battery is connected negative ground - reverse those leads.
5. It is always a good idea to remove one wire from the coil primary to prevent other parts of the circuit from altering readings. If you disconnect the wire that runs from the coil to the side terminal on the distributor that will isolate the coil for readings.

[Rudi]

Stanton:

I have similar problems with my 47 Granny. She hasn't run since CubFest Northeast NB 2009 26 months ago.. mostly because I was busy so she just sat there. Been through everything. Mag was timed correctly so no need to play with that part. However we did muck with the rotor and sure wish I hadn't. That was a big part of the problem -- rotor was out of time. Valves ended up stuck, very very low to non-existent compression from sitting so long and she still had the original spark plug wires it seems from the factory.

So after a while of playing with it, scratching my head, talking to a guru or two ... she is now back in time, fires properly and in order, has good fuel flow, has spark and has air. Still no start but getting there. I just ran into similar problems with the cap as well. I am no expert.. just sharing what I just went through. And I am pretty sure of what will have to happen to get a good start outcome.

1. The test above says to "Turn on the ignition." Does that mean only turn on the switch, or turn on the switch and engage the starter?

In your case that means to pull the switch to the on position.

2. What's the purpose of placing the center wire 1/4" away from the block?

So that you can see the spark jump from the cable to the block. You can also use a spark tester to observe this similar to this one:


Inline Ignition Spark Checker

3. Also, if no spark, could it be due to the burnt out points under the rotor cap?

While this is not exactly what Eugene may have meant the answer can be yes. In my case the center point on the cap was burnt thus creating an intermittent spark. Good spark at times and at others no spark.

From what I see you have a burned cap. Replace it then try starting again.

and is see BD got in before I got it written again.. man he is quick

[Eugene]

Need some clarification:
1. The test above says to "Turn on the ignition." Does that mean only turn on the switch, or turn on the switch and engage the starter?.

Turn on the ignition switch, no need to engage the starter.

2. What's the purpose of placing the center wire 1/4" away from the block? .

You are looking for a spark at the 1/4" gap.

3. Also, if no spark, could it be due to the burnt out points under the rotor cap?.

At this point in the initial test, the magneto points are not involved. You are using the wire removed from the side of the magneto as the points. Touching and removing the wire removed from magneto is substituting for the points.

4. I have a multimeter. On the advice above, do I leave the black lead from the multimeter on the side post at the magneto and start using the red (positive) lead at each electrical connection until I see voltage?.

Digital reading multimeters - it doesn't make any difference. Analog (needle) positive/red lead to ground.

5. Can I test the ignition coil while it's still connected to the tractor's wiring or do I need to remove the wiring to/from the coil?.

The coil is disconnected from the tractors wiring when you open the ignition switch and remove the wire from the side of the magneto.

[Stanton]

Thanks for the clarification, guys. I'll take this home, give it another try and let you know.

[Rudi]

Oh yeah, Stanton I forgot to tell you what the solution for my problem will likely end up being. I had a little help from a trusted mechanic and a Cub guru on this cause it was getting really confusing. Tried to start with the 6v battery .. nope Granny not having any of that at all, tried boosting with a 12 v --- nope no joy there either. Added starting fluid cause I ran out of carb cleaner -- nope she wasn't having anything to do with that either. Oh.. it was sooooo close, she is trying to start but just isn't happening. Good clean non-ethanol fuel in the tank and she doesn't like that either.

Pretty much accepted that I will have to pull start her to get her going. That may be the route you will have to go as well. Not sure what causes this situation but it is the second time ...

[Stanton]

Pretty much accepted that I will have to pull start her to get her going.

I've never pull-started a tractor before. Obviously, a running tractor pulls the non-running tractor, but beyond that, how's it done?

[RaymondDurban]

I've never pull-started a tractor before. Obviously, a running tractor pulls the non-running tractor, but beyond that, how's it done?

Same as you would a 5 speed truck or car. Connect the vehicles with a long strap, with the non runner in tow, put the trans in second or third, hold the clutch in with the ignition switch and fuel on, get moving and then release the clutch pedal. The tractors wheels will back feed through the transmission and cause the engine to turn, which will hopefully crank the engine. A long strap is recommended to give you a bit more time to push the clutch back in after the engine cranks to keep you from running into the back of the tow vehicle.

[lombard]

JIM BECKER------YOUR A NIT-PICKING-PROOF READER

MOST PEOPLE READ FOR INTENT-----SOME TIMES READING
BETWEEN THE LINES-----


GOOD LUCK
LOMBARD------SC-------

[Stanton]

First of all, I sincerely appreciate the opinions and comments from each of you.

Secondly, something I want to double-check: I noticed that when I hand cranked the engine around to TDC, the magneto clicked just past the notch on the pulley. Is the "click" supposed to happen just before the notch, so when the magneto is tripped the notch lines up perfectly with the pointer, OR does it "click" just at the notch so it's about 3/16" past the pointer?

The thought occurred to me that perhaps Nellie got out of time at some point, but I feel the problem is in the distributor cap (slightly burned points under the cap).

Thanks!

[Bigdog]

Stanton - the click should occur just at TDC. That's why we set the timing mark on tdc and then rotate the mag to get it to trip. The arcing under the cap is an indication that there is a problem with the cap / rotor button. Since you are using the distributor portion of the mag make sure the rotor button is in time with the drive. It could be that the rotor button is not on center when ignition occurs. The arcing usually comes from moisture in the cap and once a carbon path is established the problem only gets worse.
Have you confirmed that you are getting spark from your coil yet?

[RaymondDurban]

It should click right at the notch. If it's just a hair after, I don't think it'll matter too much, but you definitely don't want it before the notch if you ever try to hand crank it. It could fire the engine backwards and hurt you if you still have ahold of the crack handle.

[Stanton]

Stanton - the click should occur just at TDC. That's why we set the timing mark on tdc and then rotate the mag to get it to trip. The arcing under the cap is an indication that there is a problem with the cap / rotor button. Since you are using the distributor portion of the mag make sure the rotor button is in time with the drive. It could be that the rotor button is not on center when ignition occurs. The arcing usually comes from moisture in the cap and once a carbon path is established the problem only gets worse.
Have you confirmed that you are getting spark from your coil yet?

I'm not getting a spark at the coil-to-engine block when the magneto wire is removed-retouched to mag post.

I plan to work on it this weekend. I'll let you all know.

[Eugene]

I'm not getting a spark at the coil-to-engine block when the magneto wire is removed-retouched to mag post.

Not what I intended. If the points are open you will not get a spark.

Remove the wire from the side of the magneto. Ignition switch on. Touch the bare end of the wire removed from the magneto to a ground - such as the side of the magneto or engine block. Look for a spark in the 1/4" gap from the coil wire to ground/engine block.

What we have done is split the ignition system in half. One half being the wiring, coil and ignition switch. The other half being the distributor (points, rotor, distributor cap, etc.).

If you have no spark with the described preliminary test, the problem is in the wiring, coil, and or ignition switch.

[jfavor]

I'm wondering something. If this tractor originally had a mag which has been converted to a distributor.... When the switch is pulled to the on position now it's actually off. So the switch would need to be pushed in to start and pulled out to turn it off. Is this correct?
Jim