I bought a 54 NAA from a guy a week or so ago and I'm stumped. Tractor fired up, ran around his yard, picked up a 5' Box Blade and drove onto my trailer then stalled out and battery died before getting it started again. No biggie, older battery, had started and stopped a few times so maybe not much recharge time. Already converted to 12V Negative ground so easy enough to figure out if it's charging once I get it started again. Get it back to my new house (4 acres so the NAA is perfect size), throw a jump box on and it fires up just fine. Get it off the trailer, take a quick victory lap and head towards the shop maybe 1000' away to check the charging system and change fluids, etc. before putting her to work. Kick it in 4th, add throttle and it makes it maybe 200' and dies. Won't restart and run the jump box dry. Tow it the rest of the way to the shop and pull a plug (black soot but not wet), getting spark. Grab a tune up kit, change plugs (.025" gap), cap, rotor, points and condensor look new but change the cap and rotor because there's a smudge on the tip of the rotor and I'm already there. No start. Look at the ignition switch and there's maybe 3 strands of wire still connected, A-HA! Replace the switch and still won't start. Give it a little taste of starter fluid to the carb and it backfired... so here I am asking where I should start poking around next. Previous owner also said he put a new, rebuilt head on it recently AND the radiator is leaking from somewhere around the bottom corner near the hose.
I've moved on to other problems since then like the alternator being bad (but I have multiple good battery chargers to keep things topped off for now). The new issue is a leaky rear wheel seal pushing out grease needing a new widget to turn the new cable for the new proofmeter... but otherwise she runs well enough to drag a 40 year old bradford pear that fell over last wind storm in a minimal amount of pieces. Also helped to clear 2 acres of weeds with a 4' box blade and get the land relatively level again. Winter is coming fast and I'll get some fresh paint, seals, new alternator and maybe even some 12V headlights for her. The widget worked long enough for me to verify the rpms were where they needed to be on the throttle stop to run anything on the PTO for the meantime.