Spark plug wires/boots question

xs650brat

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Looking to switch out my yellow spark plug wires on my '78 XS650 Special. A few questions that I'm looking for clarification on:

1. Can anyone point me in the direction of the right NGK boots and a set of black wires appropriate for my bike? Running NGK BP7ES plugs and the coil as pictured below.
2. The wires are replaceable on this coil, right?
3. What is the connection like between the end of the wire and the coil?...what's inside that screwed on collar?
4. How does the boot attach to the wire?

I'm sure this is basic stuff...but I've never replaced spark plug wires on a bike before. Tools required, tips and tricks all appreciated before I purchase wires and boots, pull the tank and get in there.

IMG-4942.PNG
 
Go ahead an unscrew those black plastic caps and then unscrew the plug leads off of their center screw mount. That is a maintenance task to do anyway to look for corrosion. You’ll see how the new leads will screw back on that center inside the coil receptacle.
 
I've just bought a set of NGK LZFH plug caps and a set of BP7ES plugs. Thanks for reminding me, it's a good idea for me to change the leads too.
 
The LZFH caps are non-resistor, as are the BP7ES plugs. That's fine if you're running points but if you have an electronic ignition, I think most like a resistor cap or plug.

The NGK plug caps screw onto the wire. If you look into the wire hole, you'll see what looks like the end of a wood screw in there. It's made to "screw" into the end of the plug wire. The stock coils may have the same thing, or may just have what looks like the end of a small nail. If that's the case then you just push the wire onto it. Also when you unscrew the cap at the coil, you should find a little rubber "doughnut" on the old wire. That gets compressed when you tighten the cap, pinching the wire and holding it in. So, you'll need to transfer it to the new wire. To insure good contact, I like to prep the ends of the plug wires like so .....

Plug Wire End.jpg
 
The NGK plug caps screw onto the wire. If you look into the wire hole, you'll see what looks like the end of a wood screw in there. It's made to "screw" into the end of the plug wire. The stock coils may have the same thing, or may just have what looks like the end of a small nail. If that's the case then you just push the wire onto it. Also when you unscrew the cap at the coil, you should find a little rubber "doughnut" on the old wire. That gets compressed when you tighten the cap, pinching the wire and holding it in. So, you'll need to transfer it to the new wire. To insure good contact, I like to prep the ends of the plug wires like so .....

View attachment 259097
So the boots are SUPPOSED to come off. That makes me feel better... mine must not have been screwed on right cause they fell off when I popped them off the plugs.

I love finding these pictures... they make my brain a calmer place.
 
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