8n - front mount dist - plug 1 & 2 fouling

Wade C

Member
Been arguing with my dad's 8N... (6v, front mount dist, I think late 40's - I know its a low serial number) He had me come get it to see if I could figure out why it was running so poorly. He had had it worked on (tune up and carb rebuild less than 10 hours or run time ago) but after he got it back, it lacked power under load, so he adjusted the carb according to the manual, and it was pretty good, but a bit harder starting. Ran fine until he shut it down, and the next time he started it it would barely start and was sputtering like mad.

I did some digging, and found points in bad shape (sort of expected that) and plug 1&2 fouled, so I thought I had it licked. Replaced points, condenser, cap, rotor, gaskets, set/checked the timing, new Autolite 437 plugs, and checked the firing order/plug wires.

No dice, still sputters, and plug 1 & 2 are fouled (soaked with gas).

Looked at plug wire ends, thinking maybe (though they looked new) that they were cut to fits, and whomever did the cut and fit - maybe did a poor crimp job. Well, I was right, poor crimp job, but also, carbon core plug wires, not copper core. But I dont know just how big a deal that is. I re-crimped the ends to make sure they are making good contact - but no change.

One other oddity, was before I tore into it, I noticed the battery wire on the generator was burned. I dont know when or how, but evidently, at some point it either shorted there at the generator or somewhere close, as it isnt burned up the harness. But I know so little about the generator stuff (got into mechanics when the internally regulated delco alternator was common place). But I thought I remember hearing about a generator causing issues with ignition stuff if something went haywire. And, when I pulled the belt to get the dist. off to replace points, I noticed the front bearing out on the generator as well. So lots of things all at once, but Im unsure if there are any correlations here.

Considering some of the other work that needs done we want to make sure we can get it running right before doing other work to it (like the generator - or had contemplated a 12v conversion - but not willing to put the money into that until its running right).

Anyway, planning a compression test here shortly, but looking for other things that might be more common and specific to the 8N or something Im overlooking. I wouldnt think a bad coil would give me a good spark on 3 & 4, but not 1 & 2... but sort of running out of simple ideas or things that dont cost a bunch of money for parts we might change anyway if we do the 12v conversion.

Anyone have any ideas?

Thanks a bunch
Wade
 
First, replace the plug wires with copper core
wire. Carbon core wires often have too much
resistance for the old 6V system. This is
necessary no matter what else you do to the
ignition system.
 
Wade........its NOT yer squarecan coil its yer carbon core (glass) sparkie wires. They BREAK inside the insulation from handling. Gitt some real COPPER CORE sparkie wires (cut to fit)

You do know ittza 2-bolt, 15-min job to replace the points (0.015") on the kitchen table, don't you? Just un-snapple yer capple and letter dangle. Remove yer 2-bolts and take a walk to the kitchen. Installation is a reversal of the removal ...except... finger start the 2-bolts and put the rotor on. Now rotate the rotor so the OFF-SET tang fits the OFF-SET camshaft slot. Now tighten the 2-bolts and re-snapple yer capple. Simple, eh?

Because yer weird 4-nipple frontmount dizzy has an OFF-SET drive scheme, you can NOT install it outta time.

Remember to "polish" the INVISIBLE corrosion from between the points (0.015") after installation. Me? I clamp a clean $1-bill between the points and pull. Iff'n yer really cheap, tear a strip from HEAVY brown grocery sack and use that. .........Dell, yer self-appointed sparkie-meister
 
Geeze, I hate to pile it on, but, copper core plug
wires. You might have ~low compression and a
reasonably decent running tractor.

I almost replaced an Ignition Module on my non
starting Geo, till someone here mentioned the
wires. I think damp weather will accent the PW
problem.

BTW, atta boy for helping your pappy.
 
Thanks for the input everyone.

I was really curious about the carbon/copper wire thing, as theoretically, I could see issues, but had no experience to back it up to justify the cost of replacing already new plug wires.

Ill get that going and see where it leads - in the mean time, will check compression. Its always been a decent starter, and ran well... just something happened between the last, and second to last time Dad ran it.

Dell:
Yeah, I know its a 15 minute job, as I just did it yesterday before I started inspecting the wires. The ones that were in there, supposedly only had 10 hours on them, but had obviously welded together or something cause there was a huge divot out of the stationary point face and a sharp build up on the moving point face. So I replaced them, thinking I had the fix... But no such luck. But didnt clean the "invisible corrosion" you mentioned... had never heard of that, so will do that as well just to eliminate possibilities. Guessing its a light oil coating or something that causes a bit of oxidization?

But the copper wire vs Carbon appears to be a big thing...which I wondered if it might be - so will get on that first, and then see where I end up.

Thanks a bunch, and any other input, ideas, or suggestions are welcome.

Thanks
Wade
 
Good points for a N tractor with a front mounted distributor are getting harder to find. If you buy a points set at Tractor Supply or most AG stores what you get is junk made by TISCO. They mostly likely will only last several hours of operation. I either buy Blue Streak points from this site, points from nnalert or from NAPA. The Blue Streak are the best but very expensive. The other two are second but far better then that TISCO junk. TOH also sells a tool to use that makes setting the timing on a front mount much easier then shown by the manual.
 
Wade........you write......."The ones that were in there, supposedly only had 10 hours on them, but had obviously welded together or something cause there was a huge divot out of the stationary point face and a sharp build up on the moving point face"........the "divot and build-up" are the result of BAD condenser. That is what yer condenser is supposed to do, PREVENT burned points. Condensers are known to be BAD right outta the box. Dig yer OLD condenser outta the trash and re-use it.

Condensers don't wear out, but most shadetree mechanics have NO WAY to test condensers so its automatically included in all points sets.

No telling where or why yer points (0.015") gitt INVISIBLE corrosion, just you gotta clean'em just as I recommend after installation. ($1-bill) Many feeler gauges (0.015") are oily to prevent rust. ........Dell, sparkie-meister
 
I wasnt the one that replaced them last time. Local mechanic did it. So I got nothing I can dig out of the trash. Im the "last resort guy" that usually gets things after local shops dont do it right or cant get it done because parts arent available anymore (I get the fun of making some things from scratch), mainly because I live far enough away from my folks that its just not all that workable for me to "fix everything" - I just get things when they are either close by, or been through the motions with others, and I get the "dig in, find the actual problem, and do it right and to last - or make the call that its time to sell/junk what ever it is" guy...

So all I have is the one condenser that was in there with the points that had welded together, and the new one from the kit we got locally before knowing about the blue streak thing... But will try and get wires and set of points today and see where that leads me.

Wish I was better versed in the older stuff... much more familiar when we start talking computers and sensors... even my old pickups in high school got converted to newer electronics... so didnt even have to learn about it then.

Will post back with results if I get any, or questions if I dont :D

Thanks again
Wade
 

You can buy everything you need at Napa to make your own plug wires. You can buy plug wire by the foot. It's not copper core but it is stranded wire core. You can make each plug wire the exact length you need.

You can also buy the following.

90 degree metal clip ends for the plugs
90 degree rubber elbows
metal clip ends for the distributor
straight rubber caps for the distributer

I keep five or six feet of wire and a few sets of clips and rubber boots on hand so I can easily replace any wire if I have to.

I can post pictures of how to make up the wires if you need them.
 
Thanks,

Our small town Napa (or the next town over) doesnt have anything for plug wires with copper. All carbon core. So will have to order in something. Have made plenty of plug wires in the past, so not to worried about getting it done, just have to find the wire.

Was going to steal the wires off an old pickup here, that had copper wires I had put in it, but the mice decided they were too tasty to let be... so no chances there, so the boots I have here left over for points caps wont work cause they are the 8mm boots. So guess its time to order stuff from somewhere.

Thanks
Wade
 
YT has the copper core wires you are looking for.
They generally get thinks to you quickly and have
good quality stuff.
 
Thanks, been looking at the list of stuff... was hoping for plug wires with 90° on both the plug and cap ends, but appears Im either going to have to buy separate terminals/boots to get 90° at the cap, or live with the 180° versions. Just seems the 90° would route cleaner and stay out of the way of the fan belt better.

Will see what dad wants to end up doing. Was hoping to get things done today, but evidently, thats not in the cards.


Wade
 
Well, glad I didnt get any parts yet... got in and did a compression test. Since everything was apart, I just did it cold... but thought it might at least give me a hint...

Well it did. Compression on 1,3,and 4 (cold - batt at 6.10volts at the start of testing - no oil dumped in the cyls because was just looking for dramatic differences) were in the 100-105 range. But that silly little cylinder #2... Nada.... nothing, zero, zilch... pulled the tester and stuck my hand over the hole, no air movement. Covered plug hole with finger, and nothing... not even the slightest feel of air moving.

So... we have deeper problems than just plug wires for now. Now have to see what Dad wants me to do...

Anything that commonly happens on these to give me and idea what I might find if he elects to have me dig deep?

Was planning on pulling valve/tappet covers, and look for anything not moving or obviously broken (valve, etc), then on to pulling the hood if nothing appearing to be wrong under the valve/tappet covers, and the flashlight look in the plug hole test :D... and then pull the head... and then..... and then.....

Guess we'll see what he wants me to do. He's got A LOT of goodie out of this critter in the last 40 years... so not sure what he will do.

Cheers and Thanks!
Wade
 
Ramen........what do YOU think ittza means? I use it to convey information, and it called "writing style"........Dell, with 4-degrees
 
Wade,

It is easy to watch the valves work without pulling the head. On the right side of the engine are two rectangular covers. Remove the nut near #2 cylinder and pull her her off. Turn ignition off and hit the start button. Maybe you will see the problem
 
Yup, thats the plan... and then go the head if I can see nothing wrong under the valve/tappet cover.

Thanks
Wade
 
Well, found the problem... or at least one... pulled the front tappet cover off, and there in the bottom was one half of a keeper, the spring retainer with a big ding in the side of it, and the valve guide bushing retainer.

So... now we know that. The next question is, why... and from there, I need to figure out just how it needs to go back together, if there is any damage I need to look for (or just replace parts and see what it does), and decide if I need to pull the head to know for sure that things are okay, and get it back together.

So, at least I now know something... what Im going to do about it... well, thats where Ill start studying the manuals again, and come up with a game plan.

If anyone has suggestions that know these motors better than I, Im all ears on easier, faster, or better ways to go about things. The spring compressor is likely something Ill have to finagle once I know what all needs to go back where.

Cheers
Wade
 
Dell , you make me laugh, question " is that 4* top dead center" ?


Stan
9N 222933
2N with 8N motor 8N345567
8N 146710
8N 179555
8N 197904
8N 199000
8N 254079
8N 362039
 

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