I ran a new piece of wire to replace the original melted piece today. The old one was all bubbled up with bare wires, possibly touching other bits where it had melted, and perhaps the headlamp bar too. Yikes.

I only noticed because it ran very badly this morning when cold, despite roaring back form Brighton on the M25 the day before like a champ. Lots of spluttering and missing, very reluctant.

It has run fine for the rest of the day since I spliced in a new piece of wire.

By the way, I know why it was melted, when I put it all back together after doing the exhaust studs last year, when I went to restart it for the first time smoke came out form that area. For some reason the dipstick was touching the positive terminal of the coil! It was only brief, but obviously enough. I'm surprised I didn't spot it, but actually wonder if it wasn't this bad and just got worse due to the insulation being damaged.

My question to the wise is, do you think I will have damaged my coil by having this happen? Or anything else like the alternator? All the other wires look fine apart from one which had the slightest bare bit where this coil wire had melted onto it. Also now fixed. I replaced all the melted part of the wire.

Also, is it odd that it only really seemed to affect it when the engine was cold? It seems to have been struggling when it was warming up, but fine once it was there. It would start fine, just be a bit hard to drive for longer than usual, popping and spluttering. Then this morning it was even more extreme and not fit to drive until it got good and warm and even then..

Hi Ian on the race car we don't use the metal clamps on the Harley Coil as we have had a couple of times the HT leads arc'ing out on them - cable ties hold it place

Yeah, it's all a bit too much metal nearby really isn't it. I'd like some little rubber boots for where the wires attach, at least.

Ian, since it was the feed wire to the coil which shorted out, anything 'downstream' of the point of contact won't have been affected.
Have you examined the remains of the section of wire which was cut out, to see how badly it had been affected?
Depending how many strands had melted, there'd be increased resistance in the coil supply, clearly enough for the resultant voltage drop to affect the coil's output.

Ken, no I only noticed how bubbled and bare in places it was, I did it quickly and had to go back to work. I'll have a closer look at the wire tomorrow.

I have been having lacklustre electrics lately, despite a rebuilt alternator. Maybe it was this. Then more recently the awful running when the engine was cold.

Ha, drove it today and funnily enough it did run better from cold. And when warm seems to pick up better from low revs. Poor little bunny. Lol.

Couldn't find the old melted bit of wire to look at, must've chucked it.