Farmall 656 gas starter

I'm working on this tractor which was brought to me non running. All the electrical wiring was shot and I've finally got the lighting system rewired. One of the complaints was that when you tried to start the engine and it didn't start, the starter would continue to turn the engine until the ground cable on the battery was disconnected. I figured I would have that corrected with the rewiring I've done, but the starter still does the same thing. I disconnected all the wiring except the positive battery cable from the solenoid and put a jumper wire to the "s" post on the solenoid--same thing. Checked the voltage on the "s" post while starter was turning the engine and had battery voltage both there and the + solenoid terminal with the jumper cable removed. I disconnected the starter connection from the solenoid and tried it again and the solenoid worked correctly. Owner tells me the solenoid has been replaced recently. I'm pulling my hair out! When the starter is removed from the tractor it works OK. I'm wondering if maybe the spring that disengages the starter drive from the ring gear is too weak to retract the drive when the engine doesn't start. The owner says that if the engine starts, the starter works normally. OK fellas, any ideas? Thanks again!!

Not sure of the switch set up but could be a bad ignition switch if the start is part of the switch as in you have on and start on that switch seen it more then once or if a push button type starter switch it maybe sticking

Yeah, the push button starter switch on my 656 used to hang up and wouldn't release the starter when I took my finger off the button. Tapping/banging on the button would release it. I just replaced my starter button to correct it.

Had exactly the same problem with a 656 that I was repairing for someone else. I knew that the local shop had supplied the "rebuilt" starter. I returned it to them and when I got it back, it did the same thing. I wasn't taking no for an answer so I took it back again. They gave me a different starter and the problem was solved. They said that one that they gave me had a "beefier starter drive". Now I don't know what that means but I do know that the condition you and I had is unacceptable and dangerous and not to be lived with. Eventually what will happen, is the coating on a cable is going to start on fire and who knows what will ignite after that. I speak from experience with a 450 years ago.

Neither switch is the problem as I isolated the system to only the starter. I'll talk to the owner and find out where he had the starter repaired or overhauled and see if they might have a heavier duty starter drive etc. Thanks guys

I typed a more detailed reply last night but in the editing process I deleted it. If the switch is not the answer I know that in the automotive relm Delco starters would have that problem if the starter drive retaining snap ring and/ or it's outer retaining collar break or come out of position. The ring is (or should be) on the drive end of the starter between the drive and the nose bushing.

The 656 gas uses two different ring gears and starter drives. Confusing as heck unless you have the service bulletin that shows when they changed it. Neither drive is heavier duty , just different number of teeth. Now the 706 gas uses two different starter drives also BUT, they use same ring gear and changed the starter end housing. Confusing, yes.

Thanks to all of you for your help. PROBLEM SOLVED!!!!!!!! And a special thanks to "used red mn" as that's what the problem was.
The snap ring inside of a the washer type spacer was worn out so I just added a couple of 1/2" machine washers in between it and the inside of the outer support. Works fine now. Thanks again.

I typed a more detailed reply last night but in the editing process I deleted it. If the switch is not the answer I know that in the automotive relm Delco starters would have that problem if the starter drive retaining snap ring and/ or it's outer retaining collar break or come out of position. The ring is (or should be) on the drive end of the starter between the drive and the nose bushing.