Problem starting my Cub

[boldpsi]

all,
home now
dave

[staninlowerAL]

Hi Dave, sorry you have had such difficulty. If I were going to try I would repeat what the shop did by: 1) get a good HD set of jumper cables and connect the neg (ground) from the battery to the case (housing) of the starter. 2)Connect the other cable (pos) from the battery to briefly touch the post on the starter. This should make the starter run like the shop test. WARNING torque will make the starter move around so be prepared!! If the starter runs, remount it on your cub after you clean the contacting points because this is the starter ground. 3) Reconnect the jumper cables in the same manner with both jumper cables. Your cub starter should turn the engine. If not, you have a bad ground. If it does, disconnect the ground jumper cable and test again, if the starter does not turn when you touch the pos jumper to the starter post, you have a bad ground. 4) Reconnect the pos side of the starting circuit and test, if the starter does not turn when you attempt to start it there is an open circuit between the starter and the battery. Good luck. EDIT: There is one other possibility that comes to mind--unlikely since it has not shown up during the rebuild and testing. An intermittent open circuit in either the field windings or the armature can cause a situation like this but again it is very unlikely in this case.

[boldpsi]

staninlowerAL,


when i brought the starter back today, i mounted it and reconnected everything, including the presumably bad solenoid. i got the exact same results.
however, tomorrow i will do as you prescribed above, and report back to the group.
you da MAN, stan...
thanks again,
take care,
dave

[boldpsi]

Stan and All,
So, i did as you prescribed:
Step 1...
Removed starter.
Connected Neg cable to Neg battery pole, other end of Neg cable to knob on end of starter.
Connect Pos end to Pos pole, then touched starter bolt.
Eureka! Starter spun.
Step 2...
Install starter and repeat steps... and....
Nothing.
So, I "have a bad ground".
Where is it? Lol... meaning, how do I diagnose that?! What, the tractor itself is not "grounded"? I know that's stupid, but what does it mean?!
Making Progress... I think!
Save

[Don McCombs]

When you reinstalled the starter, did you clean the interface between the starter casting and the engine block? That interface needs to be clean, shiny bare metal.

[Mht]

I’ve been following this post but have not responded until now. It seems that you now know your starter and battery are good. Now use your jumper cables to determine if the problem is in the ground side or positive side. With the starter on the tractor and connected use the jumper cable to connect negative battery terminal to one of the mounting bolts on the starter and then try to start tractor. If it starts the problem is on the ground side. If it doesn’t start the problem is on the positive side. To confirm that remove the jumper cable from the battery negative terminal and the starter mounting bolt. Then connect the jumper cable to the positive battery terminal and touch the other end to the terminal on the starter where the battery cable connects and the starter should engage and turn over the engine. If it does then the problem is with the solenoid, cable connections or the switch circuit to the solenoid. A volt meter can be used to eliminate the switch circuit to the solenoid

[staninlowerAL]

After re-installing the starter did you connect the jumper cables neg battery post to starter housing and pos battery post to bolt on the starter where the battery cable attaches? This is very likely the same connection setup that the rebuild shop used to test the starter and you performed in the post above with the starter removed. When you then reinstalled the starter you got no starter action or spark using the jumper cables, it's possible they were not making good contact. Note this setup using the jumper cables bypasses both the grounding of the starter through the castings of the tractor and the starting circuit through the cables/switches/wiring, etc. so if the starter is good (you have proven that it is) then it should attempt to turn the engine. When you can get the starter to work using this setup, then remove the neg jumper cable and try using the pos jumper cable connected to the pos batter post and touch the starter bolt where the cable normally attaches. If the starter attempts to turn the engine using only the pos jumper cable, your grounding circuit is faulty. Starting with the battery neg clamp, clean and inspect all the ground wiring and connections to the chassis of the tractor, including the starter housing itself. If your battery grounds to the chassis under the seat/battery box try moving the ground to another location like a shift cover bolt. Maybe the rebuild shop painted the starter housing which can prevent the starter from making good grounding contact when you bolt the starter to the chassis. Once you get the installed starter to work with the pos jumper cable you can check and repair/replace any faulty components in the pos starting circuit. I will send you a pm with my contact info if you want to talk about this. Stan

[staninlowerAL]

............. What, the tractor itself is not "grounded"? I know that's stupid, but what does it mean?!

I missed this question, sorry. My explanation would be that electrically the electrical components are "grounded" to the battery through the chassis and/or wiring connections of the tractor. Older cubs up to the change to 12v used a pos ground system from the factory. Generally speaking, 12v cubs and older cubs using an alternator for charging will be using a 12v neg grounding system. I'm sure there are exceptions to this, that's why I said "generally" speaking. One statement that has been with me for a long time is electricity is always looking for a path to a ground, without that completed path, current cannot flow. No current flow--no work (i.e. starter, lights, motors, etc will not work).

[boldpsi]

Stan, Mht, and Don,
I should have made my first sentence more like: explain it like I'm a 4th-grader
But this is exactly what you did in the last 3 posts, and now I can understand it better.
Don, I did check the housing where the starter mounts to the Cub... It is painted, not only on the exterior, but the interior as well, where the round part of the starter on the mounting flange inserts to the tractor. I did completely clean the starter, but not the tractor housing. It is all painted, so, maybe that is where I skipped a step the 10 or so of you have said to assure bare metal!
Stan and Mht, those diagnostic steps were what I needed, assuming cleaning the housing of its paint for the starter fails to produce positive results.
Again, yous guys are a gift to us knuckleheads!
Thanks, results to come soon. I bet y'all can't wait, lmao
Dave

[Don McCombs]

Be patient. You'll get it figured out.

[Mht]

If you have paint all over the starter i feel sure that is at least part of the problem. Get that cleaned up and the starter back on and try again. Keep us posted and I’m sure you can get this all sorted out and your cub to start like it’s supposed to. Sometimes those of us that work on things regularly don’t explain things in simplistic enough terms for those new to this. Continue to ask questions and you will eventually get an explanation that clicks.

[staninlowerAL]

Be patient. You'll get it figured out.

Now you are , Pretty soon , then you will say: that was simple (like the paint acting as an insulator). Sometimes it just takes a little time for it to all come together!!!

[CharlieK]

If you have paint all over the starter i feel sure that is at least part of the problem. Get that cleaned up and the starter back on and try again. Keep us posted and I’m sure you can get this all sorted out and your cub to start like it’s supposed to. Sometimes those of us that work on things regularly don’t explain things in simplistic enough terms for those new to this. Continue to ask questions and you will eventually get an explanation that clicks.

alotta truth there^^^^^^^^^^^^^^^^^^^^^

[Glen]

Hi,
If there is paint on the engine, under where the starter mounts on it, or on the starter, on the surface that touches the engine, use a medium grit sandpaper to remove the paint from the metal. Wipe off all sanding with a clean rag.
Or you could use paint thinner on a rag, but the thinner has to be stronger than the paint to dissolve the paint.
If there is paint under the starter mounting, it's doubtful the factory put it there, someone could have painted the tractor with the starter off, or someone could have had the engine out of the Cub for a rebuild, and repainted it then.

The castings of the tractor have to have bare metal where they touch together, so the electrical system will ground through the tractor, they shouldn't be painted.
That is how the system can ground when the battery ground cable is attached to the side of the battery box, or to a transmission bolt. The cable at the battery is making contact with the mounting of the starter through the castings.
The mounting of the generator, or alternator is the same also, it has to have bare metal to ground.

[boldpsi]

Glen, Stan, Mht, Don, and everyone else,
I had to re-read all of these posts in order to understand Glen's last post. NOW I get that the metal tractor housing itself is the grounding connection between battery and starter and is the grounding circuit, and Stan's 12/21 post that the "starter grounds to the battery". FINALLY...
I was told that the enine was rebuilt before I bought it from the son of the original owner. So, that presumably explains the housing being painted.
Now... Last brain-teaser... How the heck was it working before?! Positive ground?
I am off to S.C. from 12/24 to 12/29. You can make it here from AL by then, Stan, so I will me et you at my house on Thursday. NOT!!!
Seriously though, your help has been invaluable!
I will definitely get there, and keep you all posted all the way!
Happy Holidays!
Dave