In Reply to: 641 wont start (2020) posted by Mike in Michigan on July 11, 2020 at 08:21:21:
Mike - If you are nearby I could come over and look at your Ford 641 with you -I sent an email with my phone number.
You could have just had the battery tested at a local shop before going out an buying a new one. New batteries can be junk out the door, mostly the cheaper bargain-house brands so don't judge performance by age -have specific gravity tested on a bench. Did you perform the fuel flow test before pulling the carb off? Are the plugs wet after cranking and no-go starting? Just replacing parts willy-nilly without proper diagnosis will only get a bunch of new parts that may or may not happen to fix a defect or until you run out of money. One issue at time. Fuel flow pass? No? Problem solve til root cause resolved. Yes, problem lies elsewhere. Wiring tested thoroughly. Distributor tuneup - points set and timed correctly? Points set = .025" +/- .001" Spark Plug gap = .027" +/- .001". CLYMER I&T FO-20 Manual and the OEM FORD Owner's Manual are your friends. Get your Essential Manuals out and go step by step -avoid shortcuts and guesswork. FYI & FWIW, the OEM 600/800 electrical system uses the 20-AMP/2-Brush 'B' Circuit Design Generator. The unit must be polarized correctly too but most likely not your problem.
FORD NAA, 600, & 800 ELECTRICAL w/TIMING:
° BTDC = Degrees Before Top Dead Center
CHARGING BATTERY & SPECIFIC GRAVITY:
FORD 600/800 TRACTOR IGNITION TIMING & ELECTRICAL WIRING:
FORD 600/800 ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:
FORD TRACTOR GENERATOR CIRCUIT TYPE:
NOTE: *The 9N-10000-A generator and everything after the NAA thru Hundred Series models are 'B' Circuit Type.