Allis Chalmers running bad again

[Oliverguy-NE Ohio]

Hi guys. Been awhile. Is that a good or bad thing?? I don’t know. But anyway got this Allis Chalmers C from an auction for 350 bucks. Hadn’t run in 5-6 years or longer. Got it home. Cleaned the carb and put a tuneup kit in it. Hot wired it for simplicity. Slapped a 12v coil and a spare battery in it. Fired right up and ran quite well. Well I’m getting ready to get it ready to sell so I put the new 6v coil back on and got a 6v battery. Kept it hot wired and it ran good on 6v. Then I tried switching over to the wiring system and I was getting 6v at the coil and it still fires up and runs but it’s pretty bad now. Battery reads 8v while running so seems to be charging. I was thinking it was a bad ignition switch or a bad wire going to the coil. I is misfiring some and just doesn’t seem as strong…I don’t think it’s the carb is dirty again because it happened right there and then right when I switched to actual wiring. Float is sticking a bit so I’ll probably pull it off again. Anyway what do you guys think?? I am getting good flow to and through the carb. Thanks!

 

[da.bees]

If it's an early model there could be a bit of corrosion on or more electrical connections somewhere. If it's a late model there could be one or more loose connections somewhere.
After further rumination , it probably doesn't matter whether tractor is 85 years old or 75 years old, corrosion or loose connection is highly possible in either case. If you list readings you saw on your vom during preliminary testing, that might help us help you.