How to Make Custom Spark Plug Wires for Harley-Davidson and Other Motorcycles
Making your own spark plug wires can be extremely fun and can take the customization of your motorcycle to the next level.
We carry a wide array of spark plug wire kits & components, as well as spark plug wire by-the-foot and all the necessary components to make your own custom motorcycle spark plug wires.
These kits work for a wide variety of motorcycles including Harley-Davidson, Triumph, BSA, Norton, BMW, Honda, Kawasaki, you name it! The same wire and components work for cars, custom vans and hot rods.
So get out those wire cutters and crimpers! Let's make some new spark plug wires together, for your custom machine!
VIDEO: How To Make Custom Motorcycle Spark Plug Wires
In this how-to tutorial video, Todd walks you through making your own custom spark plug wires for your motorcycle.
Learn the differences between 7mm and 8mm, along with how to properly and easily install the straight or 90 degree rubber spark plug boots, spark plug caps and high tension terminals for your coil or magneto.
00:01 - Intro
00:18 - What's new with our Lowbrow Customs Spark Plug kits?
00:51 - Differences between 7mm and 8mm. What do you need to use for your motorcycle ignition?
02:29 - Stripping the housing off of 7mm and 8mm to get a better look at the difference of the wires inside.
04:20 - What comes in the kits Todd?
06:02 - Installing a 90 degree boot and 90 degree connector for a spark plug onto an 8mm spark plug wire (same methods apply for 7mm).
11:00 - Testing connection with spark plug and your newly made 90 degree end. 11:31 - Installing a coil boot and connector onto an 8mm spark plug wire (Same methods apply for 7mm).
13:04 - Plugging the coil connector end to a Triumph coil to show how it connects properly.
13:50 - Installing a straight boot and straight connector for a spark plug onto a 7mm spark plug wire (Same methods apply for 8mm)
17:08 - Testing connection with spark plug and your newly made straight end. 18:00 - Outro!
18:30 - Todd goes for a ride!
How to Install Motorcycle Spark Plug Wire Caps, Terminal Ends & Boots
Todd shows you the proper way to make a set of custom-length spark plug wires for your motorcycle.
We often get customers asking how to install the ends on their plug wires, be it one of our vintage-style Cloth Covered Spark Plug Wire Sets or NGK plug caps on silicone wires, or any type of spark plug wires for that matter.
In this DIY Tech Tip Video, Todd, Head Motorcycle Tech at Lowbrow Customs, explains how to assemble your spark plug wires (even if you do not have the special crimpers made for the terminal ends)!
“Todd from Lowbrow Customs. Today I'm going to show you how to make your own spark plug wires. We have these spark plug wire kits available, they come with three feet of wire also available in various different colors. They also come with two of these Rajah ends, and two of these boots that will go over your coils. And they also come with two of the ends that will plug into the coil.
Okay, first thing we want to do is make sure you square the wire you want a nice clean cut on the end, and then you're going to strip off probably about a quarter of an inch, being careful not to cut into the core of the wire with your strippers. Then you're going to take your Rajah end. You're just going to unthread, it has threads on it. Then take this end here, and slide it over the wire. Now, you've got the wire protruding up through the middle of it.
And you're just going to thread this other end of it on to there with the point facing in, which will make the electrical connection. Nice and tight, simple. Okay, now obviously once you've got that done you should plug that onto your plug wire, and figure out how long you need it to go to the coil. And at the other end, the first thing you want to do is slide the rubber boot over the wire because it won't be able to go on after the connector's on there.
Little bit of lubrication doesn't hurt here. Okay, do I like to do these ends? What I do is I strip about 3/4 of an inch once again being careful not to cut through the copper core. give it a little twist, and fold the wire over the outside of the cloth covering. Let's give us a little bit more room to work here. Okay, then you're going to take one of these ends that will plug into your coil.
There is a fancy tool made for these to do this crimp, and make it beautiful, but not everybody has that tool in their garage. What I like to do is I'll take a pair of needle nose, and I'll just take the end that's going to get crimped, and kind of fold it over a little bit, till it looks like that. Okay, what you want to do is you want to slide the wire with the part that you stripped, and put it to the bottom so that the crimp is on the opposite side of the wire.
You also want to leave yourself a little room there so that it ends up looking like that before you crimp it so that it can engage into the coil properly. Just taking whatever pliers you have around the garage, and kind of squeeze it together, fold it down a little bit. I always want to make sure anytime you crimp something onto a wire that it's secure, it's not going to pull back off, and that's about what it should look like when you're done.
Also when you go to plug this in the coil if it's not a tight fit you can always bend these out a little bit, and then the first time you plug it in it will fit tighter. If it feels loose in the coil just bend it a little bit. We also have these NGK ends available for spark plug wires. These form a nice tight watertight good connection if you have a magneto type ignition probably not a bad idea to have these resistor caps on there. They're simple to install.
These have a point inside the end what you're going to do is you're just going to square your wire up, first you're going to put the boot over this. Okay, you're going to slide the lower boot over the wire, then you're just going to thread this in like you're screwing it. Try to get the wire, the point of the screw inside here you go right directly down the center so it's making good contact with the copper core of the wire, and you're just going to thread that on like so till you feel a tight resistance, that tells you that's threaded on as far as it will go.
Then you can slide the boot over the end of the cap. There are three little notches on the end of here, and that keeps it from pulling off. Once again a little bit of loop probably wouldn't hurt there. There you go that's what it looks like with that on there, and that also comes with a boot that you can put here. Slides over the end of that like so, so when you plug that onto your spark plug forms a nice seal.
Good option. We also have the spark plug wire available by the foot. If you want to just order the wire, and a couple these ends, you can do it that way also.”
Lowbrow Customs RTW Spark Plug Holder Video Review
Never get caught on the side of the road again with fouled spark plugs or with a frustrating motorcycle that won't start with ease. The RTW (Round-The-World) Spark Plug Holder comes complete with a cold-forged, 304 stainless steel multi-tool which allows you to swap out your spark plugs without having any other tools on hand.
The RTW Spark Plug Holder will fit on any motorcycle with a USA-sized motorcycle license plate. The slotted, investment-cast aluminum spark plug holder will mount at the top or bottom of any license plate, or on the backside of your license plate bracket as long as there is room.
Simply unbolt your license plate, bolt the RTW Spark Plug Holder in place and thread in a spare pair of spark plugs. It can also mount to a motorcycle using custom tabs or brackets.
The stainless steel wrench is held in place with a stainless thumb screw featuring a broached allen so it can be tightened or loosened by hand or with an allen wrench (not included). The wrench multi-tool includes a spark plug gapper, an inch and metric ruler, bottle opener, straight screwdriver blade and 1/4" hex driver. Spark plugs not included!
There are two versions of the RTW Spark Plug Holder, one for 14mm spark plugs, which features a 13/16 inch wrench to fit the spark plug hex for spark plug removal and install. The 12mm version features a matching 5/8 inch wrench to fit the spark plug properly.