several questions - OE spark plug wires

Joined
Feb 21, 2019
Messages
717
Country flag
Were they 45 degree or was it just a straight fitting with a bend in the wire?
just going by AN replacement -- from the pic, maybe not 45's, but appear to be angled closer to 90. looking at the pic, not sure how they're coming off the coil and routing the wire above the head and looping around and coming into the plug from the rear. something's not making sense to me - ??? the transition straight off the coil seems to be a better, more direct route - ???

 

L.A.B.

Moderator
VIP MEMBER
Joined
Nov 20, 2004
Messages
15,827
Country flag
just going by AN replacement -- from the pic, maybe not 45's, but appear to be angled closer to 90. looking at the pic, not sure how they're coming off the coil and routing the wire above the head and looping around and coming into the plug from the rear. something's not making sense to me - ??? the transition straight off the coil seems to be a better, more direct route - ???

Yes, nearer 90 (or actually is a '90 degree' as they are often not quite the full 90 see link below) terminal which isn't correct as AN seems to have made them to angle out and back to the plug as often seen but not original plus it looks too short to go over the cylinder head then down and forward to the plug.

That type of (unsuppressed) plug cap is probably about the cheapest available.
 

lazyeye6

VIP MEMBER
Joined
Feb 28, 2014
Messages
869
Country flag
I don't mean to be pedantic or disrespectful, .........but what is the point of of this discussion?
As I do find it to be of interest.
Is it about OEM correctness, or is about something else?
 
Joined
Feb 21, 2019
Messages
717
Country flag
I don't mean to be pedantic or disrespectful, .........but what is the point of of this discussion?
As I do find it to be of interest.
Is it about OEM correctness, or is about something else?
pretty much OE correctness and a learning exercise. when I bought my 74, it had a couple new moroso leads. they were suppressed and a bit too long - to make matters worse, one measured at 785 ohms, and the other at 3.3K ohms - odd since they were new and looked to be the same besides that, I went through a couple iterations of resistive and non-resistive plugs. in a nutshell, I wanted to sort out this inconsistent plugs/HT lead mess and find out what was OE, and if it was possible to replicate the HT assemblies. i'm trying to keep my 74 somewhat original and as period correct as possible, so the trivial details. like everything else, I probably put way too much time into this - ;)
 
Last edited:

p400

VIP MEMBER
Joined
Jul 14, 2014
Messages
1,139
Country flag
jaydee was kind enough to measure his OEM green RIST - SUPPRESSION - 0525 wires and the length was 9.5-10" long.

JayDeeMk3OEMWire.jpg
 

p400

VIP MEMBER
Joined
Jul 14, 2014
Messages
1,139
Country flag
From the drawings in the manuals, the coil boots appear to be a subtle angle not easily found.
Not 45, not 90, but more like 15-20 degrees.

These long angled boots on the coils were only used on Mk3?
The Champion plug caps only on Mk3?



Mk3CoilsWires2.jpg
 
Last edited:
Joined
Feb 21, 2019
Messages
717
Country flag
The Champion plug caps only on Mk3?



View attachment 17965
are you saying the WC200 plug caps are unique to the Mk3's? from the 74 sales brochure, the engine photo (front cover upper right, engine photo) clearly shows "champion" in white lettering on the plug cap. same on page 2, the black interstate, and the orange, tangerine, hi-rider, again, clearly shows "champion" in white lettering. i'm assuming WC200 plug caps. based on the cover engine pic, there also appears to be some variation in color between the black cap and the wire, so i'm again, i'm assuming a possible "green" color.
 
Last edited:

p400

VIP MEMBER
Joined
Jul 14, 2014
Messages
1,139
Country flag
As I look thru the past Norton model parts lists Andover, these same plug leads look pretty standard.

Lead length, boots, caps

1970 Interim parts list pic
1970InterimElec3.jpg
 
Last edited:

maylar

VIP MEMBER
Joined
May 13, 2007
Messages
3,087
Country flag
Yes, nearer 90 (or actually is a '90 degree' as they are often not quite the full 90 see link below) terminal which isn't correct
I wish those "not quite 90°" coil boots were available somewhere. Mine are straight out 180° and the wires come close to the motor.
 
Joined
Dec 28, 2009
Messages
3,672
Country flag
thanks for the replies. look at the pic - how good are your eyes. this is supposed to be a 74 crate bike - aside from the cable routing, does it look like the plug wire has a hint of color? to me, it doesn't appear black, but unless my eyes are deceiving me, i'm thinking a dark green or a dark blue - ???



the pictures below - this was posted on another thread. are these original wires? they appear dark green. I do know, that on other british motor products, MG's and such, some were fitted with a dark green suppression wire - ???



Yes these green wires were on my original 75 model with same white blue red paint . Wish I hadn't tossed them .
 
Joined
Feb 21, 2019
Messages
717
Country flag
Green HT cable is available in the UK from these guys
...and these folks seem to have an ample supply of NOS WC200 caps. black coil boots are readily available, so anyone looking add a little extra detail, everything's there. may not fool the rivet counters, but unless you still have your OE wires, this may be the only option to replicate the originals.

[https://www.ebay.com/itm/NOS-CHAMPI...269970&hash=item263cf8f38c:g:gJoAAOSwSnZe2QjI
 
Joined
May 28, 2003
Messages
2,188
Country flag
1. Original coil boots are 30deg from straight. With the offset coil outlet farthest away from the frame centerline, the angled boot keeps the wire from chaffing the top exhaust cover nut.
2. 9-1/2" wire loops over the top coming back toward the plug from the rear. This prevents rain from getting to the plug through the boot if it faced forward. Neither champion boot is water tight. Try blowing in the spark plug hole end of the boot?
3. I highly prefer the thin NBR (usually black) jacketed silicone (solid) wire as being much more flexible than PVC. Helps to decouple a rigid frame mounted coil from the isolastic moving engine.
4. Prefer solid wire to carbon laced fiberglass strands that I have diagnosed as failed with very high resistance possibley from the constant isolastic flexing. Bike will start and run but starts to break up with open throttle (higher cylinder presssures)... 02 NH rally tech session?
 
Joined
Feb 21, 2019
Messages
717
Country flag
the angle of the boot is only half the issue. not sure about the LS/LT coils, but the old style lucas type coils have a fixed diameter for the HT lead. on the lucas coil, it's a bit tapered, but .600 is a reasonable number. any boot chosen should have a snug, water tight fit. I have some straight boots with an ID of about .585 - .590 -- seems about perfect
 

springs75

VIP MEMBER
Joined
Jul 14, 2020
Messages
28
Country flag
75 Roadster, been off the road since 82. I'm pretty sure plug wires are original. Wire is dark green, labeled RIST-SUPPRESSION-0525. Coil end boot is black and angled approx 35 deg. Plug end is black and angled 90 deg with LODGE on both sides, secured to the wire with a small clamp with slotted screw and hex nut.
 
Last edited:
Joined
Feb 21, 2019
Messages
717
Country flag
my FIRST ATTEMPT at replicating OE type plug wires. may not fool the rivet counters, but really just wanted to come up with something close within reason. resistive wire similar to original, so back to straight copper core plugs.

 
Top