Slight modification to ASH's Ignition coil fix

[MrDavo]

The HT leads on my 1969 CL450 are rock hard, and the rubber seals around the plug caps fell apart when I touched them.

Rest assured that having read this thread, before I even think about looking for a new coil pack I will be cutting into the old one with a view to replacing just the leads, once bitten twice shy and all that.

[Erny]

Re-opening this topic.
Found I better replace HT leads on my stock coils, using above mentioned method

Can somebody recommend proven supplier of HT leads? (please recomment exact type i should look for)

[paul G]

I have used these quite a few times.

https://www.gsparkplug.com/ignition/ignition-lead?p=4


Mine have been the 7mm ones ensure you get the copper core type not the Graphite type.

Regards,

[AshimotoK0]

I have used these quite a few times.

https://www.gsparkplug.com/ignition/ignition-lead?p=4


Mine have been the 7mm ones ensure you get the copper core type not the Graphite type.

Regards,

Can't remember the 7mm stuff I used originally but Trigger and Julie bought some last year, so they will definitely know. Needs to be tinned copper multistrand conductor ideally.

[paul G]

There is also a slight modification on here somewhere which shows you that you do not have to grind/file down the whole of the raised section where the HT lead is encapsulated.
I did it by coming in around 20mm and then grind/file down about 15/20mm section and you can then cut the HT lead pull the old one out and slide the new one in and solder together.
When cutting the old one don't forget to leave enough to solder back onto  . Makes it easier to waterproof and recreate the domed section.

[Erny]

Yes, I know, it is decribed at the beginning if this thread

BTW
When i tried to measure resistance of secondary coil, I was unable to measure - not even sure if method was OK - I suppose one end of coil is end of HT lead and another is one of primary wires, correct?
I tried all, I mean end of HT lead ( I tried with and without cap and plug) and other to black or yellow (had coil 2-3 for test). Each time infinite resistance... but coil works, not sure if perfect but works...
What I did wrong?

[Bryanj]

Secondary resistance is from one ht lead to the other on a rwin lead coil as fitted to the fours

[Erny]

aaaa to the other HT lead? The only option I did not think about!!! 

[paul G]

Yes, I know, it is decribed at the beginning if this thread

BTW
When i tried to measure resistance of secondary coil, I was unable to measure - not even sure if method was OK - I suppose one end of coil is end of HT lead and another is one of primary wires, correct?
I tried all, I mean end of HT lead ( I tried with and without cap and plug) and other to black or yellow (had coil 2-3 for test). Each time infinite resistance... but coil works, not sure if perfect but works...
What I did wrong?

  didn't read back that far !

[AshimotoK0]

Here is the 7mm HT Lead that Trigger, Julie & myself have used.

https://www.sparkplugs.co.uk/beru-ignition-cable-7mm-pvc

[AshimotoK0]

I found some nice sleeping bits its black silicone rubber and although supposed to be black it's more if a really dark grey.

[the-chauffeur]

If you don't much fancy chopping the wires out of the coils, I've found that the same mix of isopropyl alcohol to wintergreen (ratio 3:1) that folks on YouTube recommend to put life back into hardened rubber parts will rejuvinate the HT leads surprisingly well. 

I'm in the middle of a CA77 rebuild and as you can imagine, the 50+ year old coil leads were very, very inflexible.  I took a length of 22mm pipe, plugged one end, filled it with the alcohol/'green mix, coaxed the brittle leads into the open end and left it standing for about a week.  The great thing about that method is that it takes up no space - and it uses very little juice.  During that time, the mix penetrated the cable outers and put a fair amount of flex back into them - and something about that mix keeps the rubber supple long after treatment.  I'm confident I'll be able to easily reroute the leads when the bike starts going back together in a few weeks' time.  I've also got a much shorter length lead from an XL350 sitting in a jamjar of the stuff while that gets torn down.

Admittedly it's not an option for everyone; the leads will never return to the way they were when they were new, and it's no substitute when the outers have frayed or cracked.  But I thought I'd mention it as a non-invasive option that might help those who, like me, find chopping into coils a little bit daunting.

[AshimotoK0]

Most of the coils I fix have broken / fatigued or  inner conductor wires ... so personally I would always opt for HT lead replacement. Also not so sure about the electrical conductivity of wintergreer stuff as I always use Refos 50 for softening rubbe/polymers.

[AshimotoK0]

https://www.ebay.co.uk/itm/SP75-Silicone-Rubber-Tubing-7-5mm-ID-x-1-0mm-Wall-Black/264420895150?hash=item3d90b6a9ae:m:mYQcKjf4DaSMrplJMeNyaaw


Closest I can find size wise to outher HT sleeving  but it's silicone rubber not nitrile.

[philward]

I've done 2 sets Ken - second set was much better due to practice. Make sure you have a decent output soldering iron as the HT lead core wire you are soldering takes the heat away from the solder point. Ref your question, I would not go too close to entry pont of the lead to solder as you want some adhesion between the lead and the miliput to stop the lead twisting when all done - the longer the depth of the grind back, the more adhesion.
I used a rotory burr in a drill to grind back and that method was quite controllable in grinding down to the wire. Also, make sure the 'mould' you make to hold the dialectic epoxy is realy secure as it can run out easily.
Don't know how Ash feels about that.