Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?

[Soundguy]

Sorry. Got carried away. The 6 volt requirement is for the points, not, necessarily the coil. A 6 volt coil should work ok with 12 volts, just puts out a hotter spark. The real problem is the points that will burn on their contact area with too much voltage. The burned area, then, will not conduct electricity and you will get no or intermittant spark as a result. You can clean the points with a file or sand paper without removing them from the distributor. Then reset the point gap, put the cover back on and try to start and run. Running under a heavy load will require a better spark than running with no load. Seems that the spark has a harder time jumping the spark plug gap when the engine is working hard.

well..that's compete non science BS.


In addition to the points burning.. that pitiful excuse for a square coil will be thermally damaged.

primary resistance for that square coil is about 1 ohm or so on a 6v system. it needs to be near 3ish for 12v.

as to spark intensity... ARC GAP and atmospheric conditions determines spart intensity. IE.. pressure ( compression ) and makeup of the atmospher, and distance the arc must jump.

when voltage potential is at sufficent level to jump the gap.. it jumps. it doesn't set around and wait till it gets higher and then jumps.

IE.. if you have a set plug gap and put a 6v coil and a 12v coil in that setup using a 12v battery.. spark potential at the gap is the same.

to get more potential.. widen the gap.

ps.. sanding points greatly reduces their lives by remoing hte hard coatng on them. also leaves micro scratches that cause hot spots and encourages mre arcing and burning due to reduced conduction surface area, leading to more sanding. many times sanding particles are left embeded in the contacts as well.. causing more of the same problems.

 

[Soundguy]

half truth.

there is a marketed '12v' coil for front mounts.. it is only about 2.5ohm primary resistance and still needs serieal resistance. running with no ressitor will lead to reduced points and coil life.

btdt..

Mine has a 12V coil -- they exist in front distributor box form.

Check here...
These do not require external resistors.
8n 12v coil | eBay

 

[Soundguy]

tip of the pigtail spring looks horrible and solder covered? did it get hot by leaving the key on?

clean it up and stretch it a hair so it sets in the concave screw head.

also.. the flat tab on the coil should not aim straight down..it should stick straight out to ride the metal nub on the cap when seated.

setting points gap and static timing is covered inthe service manual.

have a straight edge and a measuring instrument ( set of drill bits can work good as well ) handy.

 

[PorkChopsMmm]

Soundguy -- thanks for the help. Could you recommend *the* service manual to use? In my searching it looks like multiple kinds are recommended.

 

[Soundguy]

fo-4 is a decent on for N tractors.

 

[PorkChopsMmm]

Thanks guys. I ordered FO-4 and it is being overnighted by Amazon, I found a local source for the 12V front mount coil (hopefully will pick up latest on Saturday) and I ordered this kit from eBay.

Complete Tune Up Kit Ford 9N 2N 8N w Front Mount Dist | eBay

I will have a busy next week swapping out all of these parts. I will keep you posted on progress -- hopefully the points are as daunting as I imagine them to be.

 

[Soundguy]

make sure it has the resistor

 

[PorkChopsMmm]

OK, good news and bad news. Since it is continuing to snow and I am getting desparate I cleaned up the distributor and put it back on with the new coil. I actually assembled the distributor and coil off the tractor to make sure the coil was situated correctly. I got the distributor back on correctly on the first try -- it was good to have daylight and a flashlight to verify the position of the "key" on the back of the distributor.

Sooo.... she started right up! Good news right? I let her idle for 5 minutes or so and then drove it down my long drive way to start plowing. I noticed something was up amiss when it struggled under load again. I let it idle for a few minutes and continued driving and then it just complete *shut off*. E.g. engine just stopped, etc. I tried to start it back up and the starter button wouldn't do anything -- no click, no turning of the starter, etc. I checked the voltage of the battery and it was 10.5V.

So I am wondering if the battery was originally low and it just happened to start or if something drained it while driving? Would the battery being VERY low make the tractor shut off? Regardless, I am going to get a warranty replacement for the battery on Monday. I do need to get the tractor moved because it is in the middle of my driveway.

Dratz. She started up the fastest I have ever seen. No starting fluid and it is ~25 degrees outside.

 

[94BULLITT]

Have you put a meter on battery while it is running to see if it is charging?

 

[PorkChopsMmm]

No I haven't. Looking back I should have done some checking when I first for it running. I never thought the battery could be low because it started right up the quickest it ever has. If I get it started again I will check.

But I guess a bigger question is if the 8n doesn't get enough juice from the battery/alternator it dies? If it shouldn't turn off, even if the battery/alternator are weak then I have a different problem.