Spark plug wires

I just inherited a 1982 XJ65J from an uncle of mine. While moving it around the shop one of the spark plug wires snagged and popped away from the plug cap. The local dealer says I need to purchase a whole new coil/wire assembly, at a hefty price tag. The coil is fine condition. Does anyone know about splicing a new wire between the coil and the spark plug cap?

 

Hey Oak, this is what you need:

Spark Plug Wire Splicer:

pw1) Aftermarket NGK-brand Spark Plug Wire In-Line Splice. This handy little device allows you to cut off a bad original plug wire and splice in a replacement piece, which is really handy, since the plug wires on the original factory coils are basically non-replacable......so if a plug wire goes bad, the whole coil is basically junk! Not real clever factory engineering, but there you have it.

This splicer allows you to extend or replace a damaged or bad plug wire, just like you would splice into a piece of electrical wire. Watertight, screw-on design is made from a high-impact plastic material and adds no resistance (0 ohms) to the circuit. Very handy and practical solution!

HCP2789 In-Line Plug Wire Splice, fits up to 8mm plug wire. Each:
$ 6.00

HCP2789SET4 In-Line Plug Wire Splice, fits up to 8mm plug wire, set of 4:
$ 20.00


And I have them in stock!

http://www.xjbikes.com/Forums/viewtopic ... t=135.html

 

Chacal has wire splices in his long list of things for the XJ. If it just came out at the cap you might not need it though. The cap has a little screw in it and it just screws on the end of the wire.

Good Luck,

 

Weird thing... When I was checking my plugs with the wires hanging loose, I'd walk or look away and came back twice with the boot off of the #1 wire once and #4 wire once. I was like WTF? I just shoved them back on - no problem.

I can't imagine why the boots just fell off. I am sure it will be an item to fix in the future...


Rick

 

Rick, the boots actually "screw" onto the end of the plug wire...there's an internal coarse-threaded stud (kinda like a machine screw thread) in that boot/cap that threads and bites into the central conductor of the plug wire.....if you don't have a good solid connection there, you'll reduce the spark energy getting through to the plug, as well as increasing the secondary resistance of the coil---not a good think. Better double check all those boot-to-plug wire connections!

 

Hello!
How would I get my hands on a set of the NGK Spark Plug Wire In-Line Splicers? Also do you have bulk spark plug wire for sale. I need to replace all the wires on my 1982 XJ750J. The previous owner just wrapped rubber tubing around the defective wires!

Also, when I checked my valve clearance all but one were too tight by .001" Is there any reason for this other than someone putting in the wrong shims?

Thanks!

 

Hello bferree, I do carry the NGK plug wire splicers, but not the plug wire itself:

http://www.xjbikes.com/Forums/viewtopic ... t=195.html

Spark Plug Wire Splicer:

pw1) Aftermarket NGK-brand Spark Plug Wire In-Line Splice. This handy little device allows you to cut off a bad original plug wire and splice in a replacement piece, which is really handy, since the plug wires on the original factory coils are basically non-replacable......so if a plug wire goes bad, the whole coil is basically junk! Not real clever factory engineering, but there you have it.

This splicer allows you to extend or replace a damaged or bad plug wire, just like you would splice into a piece of electrical wire. Watertight, screw-on design is made from a high-impact plastic material and adds no resistance (0 ohms) to the circuit. Very handy and practical solution!

HCP2789 In-Line Plug Wire Splice, fits up to 8mm plug wire. Each:
$ 6.00

HCP2789SET4 In-Line Plug Wire Splice, fits up to 8mm plug wire, set of 4:
$ 20.00


In regards to the valve shim clearances, individual engine's mechanical conditions and circumstances may results in valve clearances getting either tighter or looser over time, depending on which parts are wearing more quickly. So it just may be a characteristic of your particular engine. Or it could be that the previous owner(s) adjusted the valve incorrectly! Either way, you'll want to adjust them correctly, and in your case, the sooner the better, since valves that are too "tight" can easily lead to burned valves and other difficult-to-solve problems. I also carry a full line of both original and reproduction valve shims and the shim bucket tool you'll need. PM me if you need more info and shipping quotes.

 

long story short, one of my spark plug caps was accidently pulled off the wire back during christmas break when I had compression problems. just now getting around to finishing the upper engine rebuild whenever I go home again; next time will be Easter which will be here before we realize it and I want to get the bike running over Easter break

here's what the end of my spark wire looks like with only about 3/8" of the exposed wire (if I recall correctly; I haven't been home in a while).

NOTE this isn't my wire but I wanted a reference picture to show you fellas (plus my fingernails arent' that dirty lol). will the cap be able to screw back on to the wire? I'm just confused as to what may have happened (is it ruined and not repairable?) and how to go about putting the cap back on, if possible...(?) thanks for the help guys

 

Help me out here. I'm slightly confused Moellear, the wire in the pic isn't your existing wire, so what exactly are you trying to show us? The stock wires are a copper stranded core that the stock (or NGK replacements) screw onto. They will be cut flush with the jacket, not stripped off like the carbon/silicone core type. I doubt the carbon/silicone core type will work with the stock boots but I've never bothered to find out, so I could be wrong. Anyone got some experience with this issue?

 

Cause who would admit those are your fingernails! ouch..bet the ladys dig that monster claw action....sorry I don't normally post like that but that's flipin scary.

 

Geez, everyday I believe more and more that I've become a dinosour....we used to take a 1 inch brad, cut the top off and put a point on that end then cut off a bit off the bad wire, shove half the brad into it, then into the good wire with the rest, cover with electrical tape and done....not anymore, now we've got "sparkplug splicers"???

How did I ever make it this long?

I'm just teasing so don't anybody get in a wad....simply an interesting observation about things.....the good part is that I know that I'm not alone!!

jeff

 

what I'm trying to show is something similar to what my wire looks like since the cap is seperate from wire. I have not been home since march 18th but last I recall this picture closely represents what my problem is. i'm not even sure if I have the carbon/silicone type or copper stranded core type. I use NGK plugs so is it safe to assume I use stock copper stranded spark plug wire? from my research on the forums, all I understand is that its a PITA to remove the entire wire assembly from the coil pack so I'm trying to avoid that

 

On stock systems, the spark plug wire is built into the ignition coil, and is basically non-removable without major "coil surgery".

At the other end of the plug wire (the spark plug end) is the plug "cap" (also called, incorrectly, a "boot"). This cap has an internally threaded stud (kind of like a drywall screw) that points outwards, towards the plug wire. The pointed tip of this stud pierces the central metal core of the plug wire, and the cap is then literally "screwed" onto and into the flush-cut end of the plug wire. That internal stud "screws" itself into the end of the center of the plug wire, thus making electrical contact with the plug "wire".

Note that spark plug end of the plug wire is FLUSH-CUT.....it will not and should not have that long section of un-insulated wire hanging out of the end of the wire. What is shown is a plug wire that has had its insulation stripped off from the center core "wire" (the part that actually carries the electrical current), and the insulation is typically stripped off like that before a metal wire-end TERMINAL is attached to a plug wire (like in automotive ignition systems).

By the way, unlike all of the other electrical wire on your bike, which is mostly "wire" with a thin plastic skin, plug wires --- because of the large amount of current that they carry ---- are mostly insulation around a small amount of wire....there's an "inner" insulation (typically white, a hard plastic-like material) and then a black or colored outer insulating "skin" (and then, perhaps, a soft rubber anti-chafe sheath over the skin).


Since Yamaha chose to use a non-resistive plug WIRE, they added the resistance in the circuit via the plug CAP (and that's why it's a "cap", rather than simply an insulating rubber "boot" like on cars). This cap does three things:

a) provides a means to accept the plug wire (via the internally threaded stud).

b) has a small resistor within it (which goes bad eventually, and is why the plug cap needs to be replaced periodically).

c) has a built in metal "cinching ring (or rings)" that grabs the top cap (or threaded stud) on the top of the spark plug itself.


BTW, the stock Yamaha plug wires (coming out of the coil) is zero-resistance, braided stainless steel wire.........tough to find outside of these Japanese motorcycle systems.

In fact, zero-resistance plug wires made of ANY type material is getting hard to find, as that is not a common material here in the USA......most ignition mfrs. choose to use RESISTIVE plug wire material (either carbon or copper) to create the secondary circuit resistance (and perhaps also with resistive plugs), rather than have a resistive plug CAP. Motorcycle systems are one of the very few that use non-resistive WIRE along with a resistive CAP (and either resistive or non-resistive spark plugs).

There are many pathes up the same mountain, and many ways of achieving the proper resistance in the secondary coil circuit (which consists of the plug WIRE, the resistive CAP (or not), and the spark PLUGS themselves). As long as the total resistance of WIRE, CAP, and PLUG add up to the needed amount of secondary col circuit resistance, all is well.

Yamaha choose to go with the "replacable" plug cap method of creating the secondary circuit resistance, and used (almost indestructible) stainless steel non-resistive plug WIRE. On some models, additional resistance was added into the circuit via the use of resistor plugs (1986 700-X and all 750-X models).....all other models used non-resistive PLUGS. The plug CAPS could be either 5K or 10K ohms resistance (depending on model).


If you want to replace the section of plug wire OUTSIDE of the coil body itself, you can, via the use of plug wire "splicers"......you cut off the original plug wire where it exits the coil shell (leaving about 1/2" of wire, so that there is something to "splice onto"), install the splicer, and oot of the other end of the splicer, install new plug wire. Further down, at the end of this newly installed plug wire, you either use a metal terminal (crimped onto the end of the plug wire......the blue wire pictured above has its insulation jacket(s) stripped off in preparation for such a procedure), or, if you're still going to use the stock resistive CAPS, then you just leave the plug end of the coil wire flush cut.

 

chacal, I appreciate all the you provided. got a snapshot of what my situation is and I'm thinking its SOL and gotta replace the entire wire. seems like all this bike is giving me is SOL...

can this be fixed? or is it beyond repairable? also below are snapshots of what looks like somebody has spliced wires to the coil pack. any help is appreciated!





and here's another wire with the plug just about to rip off someday.



p.s. notice my fingernails. they arent nearly as gross as somebody elses

 

Moellear, your fingernails are fine, but your plug wires are more than gross......yes, someone has done a jam-up, jelly-tight really childish job of "splicing" a new (blue) plug wire onto the end of the original (black) plug wires. The blue wires are junk, they're gone, and they won't even make good paperweights, although if you, too, used enough electrical tape to tie all four of them together, you could use them as a truncheon of sorts and track the previous owner down and whip some sense into that fellow.....


We have a couple of different solutions available for you, please send us an e-mail and we will explain.

 

haha chacal you crack me up. I've done research and heard other people splicing their wires together tas well. isn't this what the PO did here? btw; under the green electrical tape was a black rubbery type of tape surrounding the splice itself. anybody done a job like this? I wouldn't have thought the splice was terrible but again i'm just a 23 year old with little mechanic experience. also, when you purchase or go to the junkyard to get another set of wires, they automatically come with the caps/plugs too correct?






I'm home for easter break and was hoping to get a ride since I haven't rode since last fall

 

Ahh, okay, after seeing these close-ups, let's forget the batons and whips and go directly to the 12-gauge solution: a blast of buckshot, at close range, will do that person a world of good.

These pictures should serve as the leading photos in the Guide Of How NOT To Do Things, soon to be published and co-authored by every "previous owner" on the planet........

 

If your primary and secondary resistances are ok, you can dremel those coils open and replair the wire properly...
Chacal has everything you need to get this straight. IIRC, Schmuckoholic has a How-To in his collection and there is a link in our DITY section on saving what you have.
Good luck!

 

just throwin it out there to see what kind of response i get. what happens if I put a new wire on and crimp it in place like the last guy did with the blue wire? what's it going to hurt? my bike ran fine like that for the past two years?!

 

Coil Surgery is easier when you know where to cut.

These measurements will help you along.

You can get High Performance Replacement Wires off a German made wreck at a Auto Junk Yard. (Bosch Stainless Core is STD on Kraut-Cans)

The trick is exposing the two Contact Points inside the Coil.