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Does anyone make up their own high tension Spark Plug Leads?

7K views 22 replies 13 participants last post by  bucksfizz 
#1 ·
Just tidying up my electricals and focusing on THE high tension leads.

I BOUGHT new ngk spark plugs and have salvaged the plug caps (either Champion or Lucas) from my parts tin.

Is it worthwhile buying the high tension lead by the metre and crimping on new terminals rather than buying a made up set?

If I do, I'm not sure what spec the cable should be, other than each length is 24 ".

Cheers.

RR.
 

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#2 ·
the cable size is either 7 or 8 mm --- fitting the caps is easy as they just screw on - crimping the coil end terminals is not so easy - there is a specialised crimping tool that does the job - either like a pair of pliers or a two part tool that is used in a vice -- using the tool is the only way (in my opinion) to get a neat crimp - however the tool is expensive and unless you intend to make up a lot of HT leads now or in the future it is not cost effective - i have managed to get the crimps in place and working using a variety of other crimping tools and pliers i have - not professional looking results but once fitted to the coils its not seen and unlikely to let go in use - i was looking at using cheaper ready made "universal" leads or off something like a Royal Enfield - then cut off the plug cap and fit an NGK ===but ended up living with my less than pretty crimps (and still looking for a cheaper crimp tool)
 
#12 ·
- crimping the coil end terminals is not so easy -
You're right wol, those darn brass coil ends are a mile of trouble, however there's a reliable way around this problem and here's how its done:

Using the preferred copper cored lead, bare about 1/4-3/8" of the wire and bend it back against the outer sheath. Insert the lead into the coil aperture (it will usually be a bit loose), tap into place alongside the lead an appropriately sized sliver of a Redhead matchstick to hold it firm. Shove the coil lead grommet down into place and you're done. :smile2:

Remember, the key component here is the Redhead match stick!! Not sure what you could use if Redheads are no available in your area.

Never had a HT lead problem in 40+ years. !! :grin2: RR

PS: Something like my mate the "Village Idiot" might have come up with !! :laugh2:
 
#9 ·
Hi R.

I selected the NGK B7ES's.

I'll definitely keep an eye on them.

If I come across a large amount of money I might even buy the Champions and do direct comparisons.

The NGK's run a little hotter than the B8ES's and might better suit my initial pattern of short rides rather than long touring.
 
#5 ·
I made up my own using a length of HT lead from a vendor.

You don't really need a special plug wire crimping tool. A multi gage wire stripper/crimper and utility knife work fine if you're careful. The hardest part I found was sliding the boots over the crimped ends. A little petroleum jelly helped with this part.
 
#10 ·
I have usually made up my own wire sets. For my Brit Bike and Brit cars, I use Bumblebee wire from the UK as it was a standard performance option and looks very nice.
 
#11 ·
I tend to make the leads a little longer than they need to be, so that I can keep the coil connected but swap cylinders if I have a misfire.
( it works if you have EI)

to he honest, I could just knock up a "testing set" rather than ride with the longer leads, but it does help diagnose some issues
 
#13 ·
yup RR that would do it -- its just that i had a roll of HT lead - the plug caps are reusable - so i bought some of the brass ferule thingies with the intention of being clever and doing "a proper job" - soon realized that getting the ferules into place and looking "factory" needed a special tool - then i found that tool was not cheap -- got a few more sets of leads to make up so i may bite the bullet and buy a tool ---- then i can also remake the leads with my "amateur but working" ends
 
#16 ·
Ive had endless trouble with the new carbon fibre type leads that have graphite fibre in place of copper. Even BMW ones...on the other hand my old 81 BMW sits out a 5 inch massive HT bolt.. maybe they simply destroy the old leads.. I buy genuine LUCAS stock of HT wire off ebay and make up my own. The ends are not rocket science and the caps just screw on.
 
#17 ·
Ive had endless trouble with the new carbon fibre type leads that have graphite fibre in place of copper.
Peter, these graphite leads appeared as a RF "suppression" type lead back in the '70's. I've generally found them OK on vehicles I've owned, though I've always purchased them ready made, if replacing them

They did get a reputation here in Oz for being a problem in that the carbon core could go open circuit, or offer very high resistance, thus causing plug misfire. To be honest, I would not use them on old Triumphs unless there was a very good reason to do so. :smile2: RR
 
#18 · (Edited)
Having dumped the old selenium rectifier and Zener diode in favour of a solid-state Sparx regulator/rectifier when re-wiring the Trident, I discovered that I needed to fit suppressor plug caps. Therefore, I bought a set of those, only to find that they didn't fit my existing plug leads. In a fit of bling, I bought some braided plug leads, and they're a doddle to crimp onto the contacts at the coil end. Whether or not you like the leads is open to debate:



 
#19 ·
Indeed..that's why I buy old fashioned Lucas solid copper HT wire and fit non-restistor caps. I have found that even my BMW made leads fail after 2-3 years..on th3 other hand the spark output of an '81 R80GS is a wonder to behold, like a damm Tesla coil I swear! 35 years or riding and I am still on the same bearings...... as well.
 
#21 ·
.on th3 other hand the spark output of an '81 R80GS is a wonder to behold, like a damm Tesla coil I swear! 35 years or riding and I am still on the same bearings...... as well.
Those BMW's have always been a testimony to German engineering excellence. Britbike guys didn't like them as they appeared too wide and were expensive.
 
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