Spark Plug Caps

[MikeC23]

What type of spark plug caps are on the stock 79 xs650 specials? The non-resistor ones from Mikes XS don't look correct to me. Thanks for the help!

 

[YamadudeXS650C]

Your '79 came with 5K ohm resister caps, Mike's part number 23-3113 (OEM Reference #
• 4BP-82370-00-00)

Use the NGK BP7ES as a stock plug. Others have used an Autolite AP63 available at Walmart for cheap. The terminal end at the top of the plug is unscrewed and removed.

 

[MikeC23]

Perfect! Thank You!

 

[5twins]

The original plug caps resemble NGKs but are not marked so there's no telling for sure. They had a rather odd 8 or 9K ohm rating. The replacement of choice is, as mentioned, the NGK. You can use the 5K ohm version but if running points, you can use the no resistance 0 ohm type, part #LZFH .....

The 5K ohm caps are available in two types, the "E" and "F". That denotes the spark plug terminal type they fit, the nut or stud (nut removed). I prefer the stud type as I think they grip better .....

A note on those Autolite plugs. They have their terminal nut cast right in place and it can't be removed. You would need the "E" type plug cap for them.

 

[MikeC23]

That is some great info. Much appreciated.

 

[XSLeo]

The Autolite plugs I buy, the cap unscrews. I recently bought a few sets of Ebay because my local Wal Mart quit carrying them. Got them a bit cheaper too.
Don't recall exactly, but I think it was $2.99 or so a pair.
Leo

 

[MikeC23]

I'm giving the NGK iridium plugs a shot. They just showed up today and it snowed here in PA so it's a little too cold for a ride to test then out

 

[YamadudeXS650C]

The Autolite plugs I buy, the cap unscrews. I recently bought a few sets of Ebay because my local Wal Mart quit carrying them. Got them a bit cheaper too.
Don't recall exactly, but I think it was $2.99 or so a pair.
Leo

That was the Autolite AP63 you are talkin' about, Leo?