Spark plug leads - rubber cover for distributor

[Cosmo]

While tuning the carbs on my 68 Spider I noticed that one of the spark plug leads was arcing to a water hose where the lead fits in to the top of the distributor. I have the old style, thin green spark plug leads and the set I have has a sort of rubber boot that the 5 leads pass through that looks like it should sit on top of the distributor, but it is too small to stretch over it. If it did fit properly it would prevent this arcing. What is the function of this rubber cover if it doesn't fit the distributor - or do I have the wrong distributor cap? Is there any other way to add insulation at the point where the plug leads exit the distributor cap?

[GTV4EVR]

There is a plastic cover that fits over the distributer and held closed with a big clip. The rubber piece you describe fits on the top of it. I've always thought the primary purpose was to waterproof the distributer.

[Alfacliff]

sounds like you need new spark plug wires.
cliff

[ghnl]

Do you have the small individual boot on each plug wire - where it plugs into the distributor cap?

I agree with Ken - the distributor cover is more of a splash shield. If you have a spark plug wire with visible arcing, the wires are well past their useful limit. You need new spark plug wires!

[Cosmo]

Quote:

Originally Posted by ghnl Do you have the small individual boot on each plug wire - where it plugs into the distributor cap?

[60sRacer]

Bad supplier. The original green wires were copper, not graphite. Lousy radio receeption but good ignition. You should have individual boots on each wire, as well as the coil lead ends. The rubber piece you describe goes over a splash guard that showed up in mid 70's. Cylindrical, about 3 1/2 inch dia and 10 inches long, in two haves that fit together; black semi matte plastic a bit like the steering wheel/ignityion cover. Held together with a big wire c-clip. The rubber you have then goes over the upper end of that, which is about 1 3/4 inches diameter at the top.

Use both rubber bits. The plastic piece was for water splashing. Racers used it sometimes even. Sometimes shows up on eBay. Or drive only with the top down on great sunny days......

[ghnl]

Quote:

Originally Posted by Cosmo The wires are brand new, the arcing is going from the point of entry of the plug lead, where a small amount of metal is exposed, to a water pipe very close by. An individual rubber boot over each lead would fix it...

[papajam]

Starting with the 1750 series in 1968, Alfa installed a 'distributor & ignition coil protection kit' (part number 105.26.05.920.00). The kit consisted of six pieces; a rubber boot for the coil, a rubber top seal (the rubber boot your wires have), two half shell distributor covers and two clamps to secure the covers. The original 5mm green ignition wires did not have sparkplug wire boots on the distributor side.
Many have found, including myself, that the dizzy covers present a bit of a challenge to R&R and either shelf or bin the things. In my experience, the covers are not mandatory. However, with your bootless wires, and especially with one wire having exposed metal, I'd put boots on all the dizzy wires and be done with it.

[Cosmo]

Quote:

Originally Posted by papajam I'd put boots on all the dizzy wires and be done with it.