Bad spark plug wire?

[shevett]

So my 8N just had a full rebuild. It's been running a little sketchily, sounding like it wasn't running on all 4 cylinders. I pulled the cap on cylinder #1 and Heeeey, that was super-loose. The end of the wire wasn't even touching the plug. Well that'll do it.

Problem is I can't seem to get hte wire to mate with the plug. Is this just too bent up to be useful? Should I buy a new set of plug wires and redo them? Routing through that wire tube seems problematic.

 

[HFJ]

if it won't mate, absolutely time for one that will. electrician's fish tape makes feeding the wires thru the tube easier.

in a pinch, fasten the new wire to the outside of the tube. like Red Green says - "Spare the duct tape, spoil the job."

 

[shevett]

@HFJ Thank you, that's good advice. I can use any wire that's the appropriate length that I can scrounge from the local auto parts store, right? I'll probably do the outside of the tube approach (zip ties!) for now. Thanks!

 

[Indiana Ken]

The plug wire does not have to make a tight connection, like low voltage circuits require. The spark can jump from the wire to the plug and fire across the gap. In fact, there have been spark plugs made with a built in gap; these are called "booster gap plugs". I am not recommending these plugs only pointing out that a loose wire may or may not be your problem.

If you remove the 4 plugs, you should see a difference in the plugs that were firing and any that were not. The non-firing plugs should appear darker and possibly wet. Once you confirm the problem, then new wire(s) are in order. I have several 8Ns and do not use the wire tube. Note, if the tractor has been converted to an electronic ignition (no points/condenser) you may need resistor wires rather than solid wire.

 

[BradCNY]

If that plug is the furtherest from the radiator, that is cylinder #4.
I wire tied my plug wires to the outside of the tube and I ran my coil and alternator wires through the tube like it looks like you have.
A pair of needle nose pliers might be able to straighten that plug end as it doesn't look that bad.

 

[Caryc]

You can buy spark plug wire by the foot at Napa. You can also buy the metal ends needed and the rubber boots.

 

[Jim L WA]

BradCNY made a good observation. If you are thinking that is number 1 cylinder, than perhaps the firing order wrong which would cause your tractor to run sketchy. It's 1-2-4-3 front to back, C.C.W.

 

[shevett]

BradCNY made a good observation. If you are thinking that is number 1 cylinder, than perhaps the firing order wrong which would cause your tractor to run sketchy. It's 1-2-4-3 front to back, C.C.W.

I'll double-check the firing order, I got the cylinder number from a quick google lookup - probably that was wrong, but I'll definitely read off the distributor cap and see how it's wired.

 

[wore out]

So my 8N just had a full rebuild. It's been running a little sketchily, sounding like it wasn't running on all 4 cylinders. I pulled the cap on cylinder #1 and Heeeey, that was super-loose. The end of the wire wasn't even touching the plug. Well that'll do it.

Problem is I can't seem to get hte wire to mate with the plug. Is this just too bent up to be useful? Should I buy a new set of plug wires and redo them? Routing through that wire tube seems problematic.
View attachment 68197

I don't think there's anything wrong with that sparkplug terminal outside of it needing to be turned a little in the rubber boot co it will fit onto the sparkplug

As to firing order and sparkplug numbering...

 

[quinnbrian]

If it's just the steel clip that goes, on the top of the spark plug, all I used to do was give it a little squeeze ( look up inside of the spark plug boot, and you'll see it come around in a "C" shape, where it clips on the spark plug head, just give it a little..very light squeeze closing the gap at the ends of the "C" just a little..try it back on the sparkplug..and redo as needed until your happy with the fit...if you go too far, and can't get it back on..stop! Don't try to hammer it on..stop.., and take a screwdriver and place down in the hole and push the open , larger again..and start again..if needed.
There are all kinds of spark plug wires some better then other..it a guessing game, until someone finds a good supplier....my 2n I just bought had wires off a car on it lol..with the same push in "spring lock " in the hole..type of ends..( distributor end of the wire set) they didn't work out too good for the last guy..two bottom terminals where broke off, out of the cap....no way to hold the wires in them anymore....
Cheers
B

 

[Mad Farmer]

If it's just the steel clip that goes, on the top of the spark plug, all I used to do was give it a little squeeze ( look up inside of the spark plug boot, and you'll see it come around in a "C" shape, where it clips on the spark plug head, just give it a little..very light squeeze closing the gap at the ends of the "C" just a little..try it back on the sparkplug..and redo as needed until your happy with the fit...if you go too far, and can't get it back on..stop! Don't try to hammer it on..stop.., and take a screwdriver and place down in the hole and push the open , larger again..and start again..if needed.
There are all kinds of spark plug wires some better then other..it a guessing game, until someone finds a good supplier....my 2n I just bought had wires off a car on it lol..with the same push in "spring lock " in the hole..type of ends..( distributor end of the wire set) they didn't work out too good for the last guy..two bottom terminals where broke off, out of the cap....no way to hold the wires in them anymore....
Cheers
B

I just did wires on my TO-20/30 Ferguson. I found Standard makes quality universal 7mm copper core plug wire sets. The 8-cyl set (804W) was less expensive than the 4-cyl set, so I got 4 extra wires. Can't use these on front mount Ns as they have straight plug boots

For the Ns with front mount you need the 90 degree spark plug boots. Standard makes 4-cyl sets (3402) and 6-cyl sets (603W). The 6-cyl sets cost less. You'll have two extra wires for a N.