I just went and bought a Allis B10 its a 66 or 7. Runs good, just rebuilt card but still having an issue with fuel overflowing the bottom intake. I did put new float in, but believe issue might be in plunger type thing on bottom of float and the clip. has anyone had any issues like that? Also what type of oil in rearend? and the final newbie questin is why do i have an extra wire hangingdown by my mag. whats it go to? theres two on magnito already which looks right this lines a third(pic 1) where does it go. comes from the engine. Anyhelp greatly appreciated.
didn't have alot of time, but was unable to locate the mystery wire, My spine is plated togethar so I'm not able to crawl all over and look, I believe the nieghbor will be home more today, so I will give it another go. you should check to see if the mystery wire has any voltage when running/not running with a volt meter. I'm thinking it's for the headlights. I'd figure if the tractor starts and shuts off with the switch the way it's supposed to then it can't be for the coil/mag. better luck today with the mystery wire hunt.
That extra wire is probably coming from the coil (armature magneto) along with another of the small black wires. The wire running to the key switch would have been white originally and probably has been replaced (maybe because of a grounding problem) with one of the black wires running into the points box.
Here's the way your wiring would have looked originally, with the larger of the black wires from the coil running inside the points box and the smaller black wire from the coil and a white wire running to the key switch attached together on one end of a bakelite insulator and the other end of the insulator attached to the top screw of the points cover.
You can find out if the loose wire goes to the coil by either tracing its route or by cranking the engine and then touching the end of the wire to the engine. If the wire goes to the coil it will stop the engine. If you find it goes to the coil you will need to tape the exposed wire end to keep it from grounding out the ignition accidentally.
These tractors didn't come with wiring for lights so unless they were added at some later time that wire could not have anything to do with lights.