Spark Plug Wire Wear

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Just me, but if they're brittle enough to be crumbling in places, I'd replace the whole set.

Plug wire insulation can fail electrically long before it appears physically worn. A dried out lead, just lying on the engine case or engine tin, can be shorting out right through insulation that appears sound. High voltage behaves very differently this way than 12V.

A quick test is to run the engine in a darkened garage and watch for arcing to grounded metal anywhere along the wires. But in this case, with dried insulation already visible, tossing the old wires is good and cheap insurance.

Which reminds me, I should probably be doing this myself, as it's been more than a few years since I last replaced them.

We often say here that a lot of 'carburetor' trouble is really ignition trouble, and this is another classic place where that trouble can start.

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Mitch, thanks for your reply.

My plug wires are fairly new and in good condition

One was rubbing aginst the carb. and now has a worn spot.

1.  Can you shoot some RTV onto the abrasion spot of the wire to protect it?  Sure.  

2.  Can you not re-route the wires to gain a little more slack so they don't rub against your carbs?

3.  IF you can remove one end terminal on the plug wire, you could slip a short length (2” - 3” sounds good) of shrink tube over the wire to where the abrasion is and shrink it in place to protect the wire.  If you’re really cool, you could shoot a little RTV onto the worn spot and then put the shrink tube right on and shrink it before the RTV cures so it will fill the void and protect the wire jacket, all in one swell foop.

4.  And, of course, you could always just wrap the plug wire with electrical tape along where the abrasion occurs.  A couple of tape layers should do it.

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OK, good. It's one of those maintenance things that's easy to forget about.

I think I'd try to reroute the wire away from the carb rather than just cushioning the wear point. Arcing wires and gas vapor don't play well together.

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I would look at getting a drain hose or electric wire protector that has fiberglass in it. to wrap it after I sealed it.

The distributor end of the wires has a 90 degree terminal.

So, to slip something onto the wires I would have to cut them off and crimp on new ones.

I thought about using something like this:

Or this, it is split:

If it were me, I’d wrap it with friction tape then cover it with the second of the two split wraps. Im pretty sure the vinyl stuff would melt.

Dave's right, that black vinyl tubing that's split down it's length melts at relatively low temps.  Any of it close to the heads (or even the case) will tend to distort and then melt.  If it's elevated and away from heat, it's OK to use.

The white cabling coils are more heat resistant, especially if it's made of Nylon.

I'd just buy a new set of wires, but you do you, Michael.