OldIHC

There might have been room for the fuel pump on the left if a gear driven mag was used. I have seen on paper that it was an option, but never seen am FA series with a mag. May be as a tractor or power unit?

I will have to look to see what side the fuel pump is on and location.

Cornbinder, I picked up a growler off of eBay just to have one. Even though you can do most of the tests with a standard meter it seems like the growler is the best test. I figure a couple of started and I will have it paid for.

I keep telling myself, "I'm not going to do that many, and $45 for an aftermarket armature is cheap enough"! I may get one, but so far have got by without.
The latest one I pulled down was cranking when removed, but very slow. Very dirty oily in side. I thought it needed a armature cut, but once I cleaned it, not as bad as I thought. Surprisingly the drive was busted but still functioning.
One problem I am noticing on these old unit. The input stud is breaking away from the field windings. I think the heavy cables required for 6 volt, combined with age in the cable, makes them transmit forces to the stud and the solder joint can't take it. If it continues, I'll have to look into welding cable for the run from the solenoid to the motor, but it will have to be supported or the same thing will happen.
Once I clean the junk out, it needs new fiber insulating washers on the stud before re soldering, the hard part is getting the joint hot enough for a good solder joint while not damaging the insulating washers.
From what I can find, the LRA on the motor is around 600, the current splits into two paths at the stud, so that connection has to be good.

I was looking at how the stud is mounted on the smaller KB truck starters and it does not look like it would be that hard if you could get it hot enough without damaging things. I have done a lot of soldering in my work days but nothing that big. Mostly PCB soldering. Many times we would use a clamp on heat sink.

What is your thought of running the positive ground to the trans or engine block rather than the starter mounting bolt? I was reading that on alot of older cars from the 20's and 30's this is the way it was. The lower starter mounting bolt on a KB 1-5 is pretty accessible but some guys are showing running the cable by the trans and around the bellhousing. Makes for a tight angle to get on the starter bolt. Plus the starter mounting bolt is pretty large for the cable loop.

Re: Ground side cable, I think either engine or trans/bell housing is fine. The thing you want to avoid is going to frame with the engine rubber mounted, then another set of connections between the engine and frame. Adds places for problems.
The starter frame is electrically connected to one side of the motor, so it doesn't matter as long as the starter is bolted tight so there is good electrical connection between it and the engine/transmission.
As far as the soldering goes, the stud passes through the metal frame, but has to be isolated from it.
Fiber washers are used, but when they get old, they get brittle and can get moisture and expand.
To get the stud replaced or clean, you either have to remove the field pole shoes and move the field ends out of the way, or very carefully bends them to get enough room.
On mine the mere act of loosening the stud has caused the fiber washers to come apart. SO I need to get the stud out , to slip a new inner washer on, then solder the field bars back onto the copper stud. Ideally I would like to use silver solder in that area, but am going to try plain tin solder with the smallest welding tip on my oxy rig.
It is hard to get enough heat where the stud is large and the bars end of the field are thick. The goal is to get enough heat to get good adhesion from the solder, but not too much that will bake off the insulation on the windings. I think propane or Mapp torches are too wide a flame, I am hoping the very small (0) tip on the oxy rig will work, otherwise I'll have to buy an 00 or 000 tip.
If the ends of the field bars were well tinned, you might be able to heat the outer end of the stud enough to melt the solder on the inside, but I am not sure you could transfer enough heat to the bars to get a good joint.
I am learning as I go. There isn't much clearance between one of the field coils and the stud, the other is 1/2 way around the frame so plenty on that one.
I think when they are made, the stud is soldered to the end of the field coils before they are place in the frame and the shoes bolted tight in position.
The screws holding the pole shoes in are notorious for being hard to remove, the way I have seen it done is in a press to keep the bit from camming out of the screw head and a long wrench on the outside of the bit. Needs a frame on the press to hold the starter frame from turning.
80 years on, I am surprised the fiber washers are there at all. I got lucky on my 1st build, the field connection was fine on that one.

Good info. It would make sense that it was soldered before it was installed but not easy to do in reverse. Is a good impact screwdriver an option. I finally bought a snap on one and it works a lot better than the cheapo one I had prior. I have never taken those field coils out but the starter I am working in looks like they were recently replaced with the rebuild. I have a few other engines with starters so I will get one that works if it is not the ground issue. I do want to test the armature on the growler just to say I did while the starter is out. I have watched a couple of youtube vdideos and it is really a variation of just testing it with an ohmmeter with it being energized. I will let you know how that goes.

All I can tell you is I have never been successful removing a pole shoe with an impact, your results might be different. Getting a good solid fit with the driver is essential, any slop and you've already lost the game.

Yep same here , correct size tool and knowing how to hold your mouth just right..

Good posts on the subject..

Cheers - Sm