'47 Cub Died While Mowing / PTO Issue?

[farmallfletch]

Hi all, I have a 1947 Farmall Cub with a belly mower. The PTO lever and more recently the gear shift have given me some issues. The other day I was mowing and it died while the PTO was engaged. It will now not start, not even turn over. Battery is charged. First I took the gear shift off and got it back in neutral, as I believe the gear shift had slipped out. I could then pull the tractor. I also eventually got the PTO disengaged (the pulley spins freely now, I believe that indicates it is disengaged?).

My first question is: will this tractor start if the PTO is engaged? Either way, my second question is: any common things that could cause the not-starting issue in this scenario? The only thought I had is maybe I have a starter issue. (My Super C sometimes won't start and I have to loosen and jostle the starter.) This novice appreciates any and all thoughts. Thank you.

[Eugene]

Engine in good condition, tractor should/will start with the PTO engaged.

Can you turn the engine over with the hand crank or the radiator fan?

No start. I would first check the battery cable connections and battery condition. Fully charged battery may not have sufficient amperage to turn over the starter.

[inairam]

There are no safety switches. I can start my 6 volter in gear and pto on if I can not careful.

When you say not start:

Do you mean DOA no noise or action at all from the starter at all? or do you hear something but it does not crank?

[Waif]

When pulling the starter lever with a fully charged battery results in nothing , it's likely power is not going through the starter if starter is good.

Oh the number of times I had nothing happen pulling the lever when a bad connection or bad cable or bad ground said "nope!"

From battery through starter switch. Make sure everything is clean and tight and power has a flow through proper sized cables and connections.

[Don McCombs]

First thing I would check, after verifying all connections are clean, is the starter switch. If it is worn, the internal contacts will not make sufficient physical contact.

[Crimson Tim]

I agree the most likely cause is a bad connection somewhere. Keep in mind you can get corrosion internal to the wires, too. On one of mine, the wiring harness is in pretty bad shape (I’m saving up for a replacement, but life keeps getting in the way). I’ve cleaned connections and electrical-taped some areas of missing insulation, but still have an occasional issue.

I can sometimes have the same thing happen. I can be mowing along peacefully, then hit a particularly dense mole hill or scalp a high spot and stall out the tractor. Usually I just restart and continue on my way. Sometimes, however, I get no response whatsoever from the starter. Sometimes I can resolve it just by poking at the wires with my foot where they pass the clutch pedal. Bottom line is a bad connection someplace.

Try using a set of jumper cables direct to engine ground and the starter to bypass any wiring issues. Expect it to spark when you make and break contact.

Follow the current flow from the battery all the way around the circuit back to the source. Don’t just check continuity, as that doesn’t tell you anything about the *quality* of the connections or wires. Do a “voltage drop test” to find where you are losing power.

Where is your battery grounded to? It was originally grounded to the battery box, which is prone to corrosion. Many people have grounded to a bolt on the transmission for much more reliable results.

[farmallfletch]

Thank you for the replies! When I say it will not start, there is no noise, no action whatsoever. The battery is grounded to one of the bolts on the gearshift cover. The wiring and starter on this tractor are old, so that makes sense it could be this type of issue. Hopefully by this weekend I'm going to check the connections and follow the other suggestions to see. I will post an update when available!

[SamsFarm]

Did you try the hand crank?

[farmallfletch]

I did try the hand crank (which has worked in the past) it didn't even a sputter. I have checked the connections and tightened everything up. The wires are old, but I am concerned as to why the hand crank did not work. I tried jumping it at the starter and also got no response.

[Glen]

Hi,
If you connected both a positive, and a negative jumper cable directly at the starter, and it didn't turn the engine over, the contacts in the switch on top of the 6 volt starter could be burned.
You can remove the switch and sand the posts to clean them, or replace the switch.
TM Tractor has a new switch.
Be careful putting the switch on again, it has 2 pieces of thin insulation inside it, at the sides. If they are not in place, the switch can short.
Or the brushes in the starter might be wornout and need replacing. When the brushes wear down a certain amount, the starter won't work until the brushes are replaced.
The starter has a bushing at each end that can get worn also.

It sounds like the not starting using the hand crank could be another problem, separate from the starter not working.
The ignition points may be burned from use, and need cleaning or replacing.
The coil or the condenser in the magneto may have quit. It is common on Cubs that the coil quits when old. TM Tractor has new points, condenser, and coil. You can look at their listings and see what they look like.
I would do a spark test and see if it has spark to the spark plugs.
Below is a post I wrote on telling how to test the power of the spark.

viewtopic.php?f=1&t=114522

[Waif]

I did try the hand crank (which has worked in the past) it didn't even a sputter. I have checked the connections and tightened everything up. The wires are old, but I am concerned as to why the hand crank did not work. I tried jumping it at the starter and also got no response.

Did you use the right cuss words?

Does the mag. click when you hand crank? If it does like it should and power gets through the coil , point, and plug wires and plugs in enough amount you can move on from there.

My 48 hand cranking means everything has to be near perfect. Or perfect! If out of tune and it takes much cranking using the starter to start , forget a cold start hand cranking.
Don't mistake being able to start it without a battery mean your Cub will start with a hand crank. It still has requirements first. And is no substitute for a bad , dirty or out of spec. component in the mag. ignition circuit.

Replaced an ignition switch one time. Boy howdy that little bugger didn't want the tractor to start! It was getting sticky again prior.

[farmallfletch]

It has been a challenging year, and I am finally having time over Christmas to try and get this Cub running again. It is a 12 volt system. All I have is a digital multimeter, but plan to buy a bulb light test today. Both the positive and negative battery cables are in rough shape. I have 12+ voltage at the battery. I have 5.8 voltage at the starter switch. It goes away when I turn on the ignition switch. I don't get any voltage at the coil (if I am testing it correctly) with or without the ignition switch on. I don't know if any of that is abnormal or not. I do not know where to test from here. I do not know if the ignition switch should be turned on or off. Reading another https://farmallcub.com/phpBB2/viewtopic.php?t=97454#p767219 where the guy had very similar issue, they said more than likely a large battery cable since it died while mowing. Does the fact that I have voltage mean it could not be the cable? I see above where "continuity" does not mean there is "quality." I am complete electrical novice. Thanks in advance if anyone can spell out very simply suggested steps.

[Glen]

Hi,
If the voltage is that much less at the starter when it is sitting, and you aren't using the starter when testing the voltage, it sounds like you need to clean the 4 cable ends, and where they attach.
Remove each cable end from where it is attached, and use fine sandpaper and sand the metal.
Wipe off all sanding with a clean rag.
Disconnect the ground cable first to avoid shorting the system, and connect it last, after cleaning the others.
Clean the connections at the battery, and the battery posts.
1 connection is at the starter switch, on top of the starter.
Check the cable ends to see if they are tight on the cables, by trying to move them on the cables. The ends need to be tight on the cables. Look for corrosion at the cable ends, inside the ends, where the cable goes into the ends.
Charge the battery fully, use a small output charger, 6 amps or so, that automatically reduces it's charge as the battery charges. It may take several hours to charge.
If the Cub has a Battery Ignition unit, there won't be any voltage at the coil with the ignition switch off. That is what stops the engine when you turn the switch off, the switch stops the power from going to the coil.
A 1947 Cub originally came with a magneto, which is different than a Battery Ignition unit.
The coil in the magneto is built in the top of the magneto, it doesn't use battery power, and has no connections for battery wires.
The Battery Ignition unit came out during 1950 on Cubs, some Cubs were changed to them, so your Cub could have one.
Below are pics from TM Tractor Parts of both units, you can see which one the Cub has.
Pic 1 is a magneto.
Pic 2 is a Battery Ignition unit.
The coil goes on a bracket on top of the Battery Ignition unit, it isn't there in the pic.

[farmallfletch]

Thank you, Glen, and others! Very helpful. I ended up getting new battery cables and cleaned all points of contact. We are running again!