In Reply to: 8N running rough posted by Jeff on June 30, 2018 at 15:56:09:
I see a few things that matter, and a few that don't. First, you say it is a '48 8N so we can assume it is a front mount distributor, However, you don't tell us if it is a 6V/POS GRN setup or a 12V/NEG GRN switch over job. That is an important detail you left out. Bear in mind that whether it's a 6V/POS GRN or 12V/NEG GRN system, if it isn't wired correctly, it ain't gonna work right. Most problems like you have are due to poor/incorrect wiring jobs. I suspect you have a bung-hole/rats nest/cobbled up wiring job and that is part of your root cause problem.Next, most quality carb rebuild kits are fine, example is TISCO. We really don't need to know a part number or who supplied it. So your dad bought a carb kit and traced the backfiring then to a carb rebuild, yet the problem persists and has done so for years. What is a ' (3-8-010) by Northern KY 'rebuild kit' that "...looks like new dist wires were installed also..."? Is it possible that you have a12V switchover job and there is an alternator now AND/OR in addition to 12V an EI (Electronic Ignition) System was added too? Cheap batteries can be junk out the door of Wally World o r your local auto parts store. Get the battery tested at your trusty local starter/alternator shop. Purchased in 2015 means nothing. The battery must sustain a charge under load. Charging it doesn't mean it is good. You say 'VOLTMETER', so that triggers another 12V thought on my part. Some fellas take the original AMMETER out on 12-volt conversions and install a voltmeter. ALL new Ford Tractors from 1939-1959 used an AMMETER, 6V/POS GRN system with a generator and a round-can cutout on 39-47 models, and a voltage regulator after 1947. Again, which do you have? A generator or alternator? You won't see any significant ammeter movement when revving the engine up. If you want to test the AMMETER, pull the light switch 'ON' and observe if the needle drops to 0(ZERO) or even a bit to the minus (-) side. Forget the governor for now. You have other issues to deal with and I'd first suspect your wiring system is all mucked up. The carb may need to be rebuilt correctly, but mo more buying any new parts until you do a root cause problem solving procedure. Get out your 8N essential manuals and read thoroughly. You need 3 things to run: Fuel, Spark, and Compression. Concentrate on the first two for now and you'll most likely discover the root cause or causes. Perform a fuel flow test on the carb, ENGINE COLD, NO POWER. Fix any problems then move on to spark. While battery is in the shop, go thru the entire wiring. You want to confirm the wiring is correct, and NO POWER to do this either. You trace wires by continuity, not colors. Go to our HOW-TO's forum, ELECTRICAL, and download a copy of "WIRING PICTOGRAMS by JMOR". Start with the basics. You want to make your grandpa proud don't you?
FORD 8N TRACTOR ESSENTIAL OWNER MANUALS: