this does not look right....

The spark plug caps are very loose from the coil cables. The wires seem frayed. Is there any way to fix this?

 

yes, you can cut about 1/4" off the end of the lead & screw the caps back in. simples

 

If I cut back the leads, won't that shorten the cable, they barely reach the spark plugs as is...

 

yes, it's possible somebody already cut them before as there's usually enough "room" to do this. You can also do as either Fitz or Rick suggested (can never remember which one ) and push a little copper earthing wire up the end of the lead so that the plug cap can "bite" into the lead again

 

also, and mind you this is my backwoods ways talkin, but you can take an old coil (if you have one) cut a length of wire from it, screw it into your cap. then take a screw and cut the head off and use it to connect the two wires i dont recommend doing this for an extended period of time, but to get you by before you get a new coil (again assuming you have to) it works

 

You can also get parts to fix them from chacal with out having to buy new coils.

 

are our coils rebuildable? i didnt think they were able to be split

 

If i remember right there was a thread out there on how to die grind out the coils and repair them.In our coils i believe they have the same thing in the coil as in the caps the little threaded stem.

 

That's what I thought as well, although in another thread (where I suggested re-checking an "infinite resistance" secondary reading at the coil instead of thru the leads, before paying for a new coil) I was told that's not the case... Dunno now :?

 

I trimmed off some of the housing around lead 1. The wires grip the post in the cap better.

These cables have definitely been cut down before. Nothing screws in to the cap. The cap and cuff just slide off freely.

I'll check around to see if the cables can be replaced without getting new, used coil packs.

 

That's strange, certainly not an original NGK cap for our bikes :? any chance of a pic?

 

Here's a pick of of the lead from #4. The cap is behind my thumb.

 

Can't really tell from that how the lead fits, but the cap looks more black then the NGK's brown colour?
Also I'd trim the bits of wire sticking out the end till they were flush to stop any chance of HT "leaking" down the side of the cap.

Just seems weird that it'd just be a push fit, most caps have like a self-tapping screw thread inside (can only see properly if you remove the rubber boot)

 

just looked at some 1986 and 85 coils on ebay. The caps do appear to be different. Interesting...

 

Slide the rubber boot off the cap and look in where the cable goes.

If you don't see a center "spike" that would screw into the cable, they're not original caps.

The wires don't come out of the coils easily, they're molded in. If the wires have been hacked already then they can be "spliced" up by the coils (the repair kit alluded to above) or the coils would need to be replaced.

You might want to be sure your wire-length issue isn't due to simple mis-routing. The coils fire 1-4 and 2-3 together; so if you mix up those pairs of wires, the motor will still run fine but the wires won't reach correctly.

 

len sells spark plug line splicers. But I'll tell you what.... for my 86 700 Dyna Coils 119.95. dyna wires 22.50(?), switch to BPR8ES plugs. $10.00, appx 12.50 in L brackets + hardware to mount the coils.... major upgrade! and cheaper than the OEM replacements.

 

If you do upgrade coils (Dyna or Accel), swapping plug wires is a snap.
I have Accel coils and 8mm wires on my Xj750J.

Maz

 

More details...I just noticed that the 1 and 4 caps are very different than my 2 and 3 caps. the 2 and 3 caps match the diagrams in the service manual. Which leads me to the conclusion that 1 and 4 are not original caps, perhaps not the original coil.

1 and 4 wires slip out of the cap easily and have obviously been cut. 4, when properly routed via the service manual, barely reaches the plug and I don't think there is good contact between the post in the cap and the wire.

Conclusion: 1 and 4 need to be replaced.

If I upgrade, I would need to upgrade both coils right?

 

Re: this does not look right.... HERE IS A PIC

Here is a pic.

It's a little confusing since I have the tucked up to work on the valve shims, but they are in order, left to right, 1-2-3-4.

 

Sitting on the Bike orientation:

LEFT Coil: #1 -and- #4
RIGHT Coil: #2 -and- #3

 

Of course. However, in the pic, the caps you see happen to be positioned 1-2-3-4 from left to right. My question is: are caps 1 and 4 the original caps? Should they be different from 2 and 3?

 

They are different.

The "Shorter" Plug Caps are "Outboard" ( #1 & #4 )
The "Longer" Plug Caps are "Inboard" ( #2 & #3 )

 

Thanks! Okay, so it is the original left coil. I'll probably still replace them, but I can test the connection first.

 

the little white band on the wires should say what wires they are if there still legible or original

 

Have you actually pulled the rubber boots off the loose caps and had a look at where the wire is supposed to go (as I and Fitz suggested)? If you do this you can then tell if the caps have the necessary thread to screw into the wires.

From the pictures the caps appear to be original NGK brown caps just a bit mucky, so it could still just be the fact that your wires aren't able to grip the thread properly &, as your wires are already very short, there are 2 solutions other than replacing the coil.

One is to buy new (copper core) plug wires & inline splicers (len sells them, as said above), another is to push a length of copper earth wire (called something else in the US, Fitz mentioned it in another plug-cap thread) up the centre of the wire to give the cap something to bite into